EP1032575B1 - 2,3-diaryl-pyrazolo(1,5-b)pyridazines derivatives, their preparation and their use as cyclooxygenase 2 (cox-2) inhibitors - Google Patents

2,3-diaryl-pyrazolo(1,5-b)pyridazines derivatives, their preparation and their use as cyclooxygenase 2 (cox-2) inhibitors Download PDF

Info

Publication number
EP1032575B1
EP1032575B1 EP98947502A EP98947502A EP1032575B1 EP 1032575 B1 EP1032575 B1 EP 1032575B1 EP 98947502 A EP98947502 A EP 98947502A EP 98947502 A EP98947502 A EP 98947502A EP 1032575 B1 EP1032575 B1 EP 1032575B1
Authority
EP
European Patent Office
Prior art keywords
alkyl
formula
phenyl
compounds
compound
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP98947502A
Other languages
German (de)
French (fr)
Other versions
EP1032575A1 (en
Inventor
Paul Glaxo Wellcome plc BESWICK
Ian Glaxo Wellcome plc CAMPBELL
Neil Glaxo Wellcome plc MATHEWS
Alan Glaxo Wellcome plc NAYLOR
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Glaxo Group Ltd
Original Assignee
Glaxo Group Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9718792.6A external-priority patent/GB9718792D0/en
Priority claimed from GBGB9727116.7A external-priority patent/GB9727116D0/en
Application filed by Glaxo Group Ltd filed Critical Glaxo Group Ltd
Priority to EP04025990A priority Critical patent/EP1510519B1/en
Priority to EP03077298A priority patent/EP1369421B1/en
Priority to SI9830528T priority patent/SI1032575T1/en
Publication of EP1032575A1 publication Critical patent/EP1032575A1/en
Application granted granted Critical
Publication of EP1032575B1 publication Critical patent/EP1032575B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D487/00—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00
    • C07D487/02—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00 in which the condensed system contains two hetero rings
    • C07D487/04—Ortho-condensed systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/33—Heterocyclic compounds
    • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
    • A61K31/495—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with two or more nitrogen atoms as the only ring heteroatoms, e.g. piperazine or tetrazines
    • A61K31/50—Pyridazines; Hydrogenated pyridazines
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P1/00—Drugs for disorders of the alimentary tract or the digestive system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P1/00—Drugs for disorders of the alimentary tract or the digestive system
    • A61P1/04—Drugs for disorders of the alimentary tract or the digestive system for ulcers, gastritis or reflux esophagitis, e.g. antacids, inhibitors of acid secretion, mucosal protectants
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P11/00—Drugs for disorders of the respiratory system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P11/00—Drugs for disorders of the respiratory system
    • A61P11/06—Antiasthmatics
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P15/00—Drugs for genital or sexual disorders; Contraceptives
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P17/00—Drugs for dermatological disorders
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P17/00—Drugs for dermatological disorders
    • A61P17/02—Drugs for dermatological disorders for treating wounds, ulcers, burns, scars, keloids, or the like
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P19/00—Drugs for skeletal disorders
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P19/00—Drugs for skeletal disorders
    • A61P19/02—Drugs for skeletal disorders for joint disorders, e.g. arthritis, arthrosis
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P19/00—Drugs for skeletal disorders
    • A61P19/06—Antigout agents, e.g. antihyperuricemic or uricosuric agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P21/00—Drugs for disorders of the muscular or neuromuscular system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00—Drugs for disorders of the nervous system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00—Drugs for disorders of the nervous system
    • A61P25/06—Antimigraine agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00—Drugs for disorders of the nervous system
    • A61P25/14—Drugs for disorders of the nervous system for treating abnormal movements, e.g. chorea, dyskinesia
    • A61P25/16—Anti-Parkinson drugs
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P25/00—Drugs for disorders of the nervous system
    • A61P25/28—Drugs for disorders of the nervous system for treating neurodegenerative disorders of the central nervous system, e.g. nootropic agents, cognition enhancers, drugs for treating Alzheimer's disease or other forms of dementia
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P27/00—Drugs for disorders of the senses
    • A61P27/02—Ophthalmic agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P27/00—Drugs for disorders of the senses
    • A61P27/16—Otologicals
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P29/00—Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P29/00—Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
    • A61P29/02—Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID] without antiinflammatory effect
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P3/00—Drugs for disorders of the metabolism
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P3/00—Drugs for disorders of the metabolism
    • A61P3/08—Drugs for disorders of the metabolism for glucose homeostasis
    • A61P3/10—Drugs for disorders of the metabolism for glucose homeostasis for hyperglycaemia, e.g. antidiabetics
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P37/00—Drugs for immunological or allergic disorders
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P5/00—Drugs for disorders of the endocrine system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
    • A61P7/06—Antianaemics
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P9/00—Drugs for disorders of the cardiovascular system
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/55—Design of synthesis routes, e.g. reducing the use of auxiliary or protecting groups

Definitions

  • This invention relates to pyrazolo[1,5-b]pyridazine derivatives, to processes for their preparation, to pharmaceutical compositions containing them and to their use in medicine.
  • COX-1 The enzyme cyclooxygenase (COX) has recently been discovered to exist in two isoforms, COX-1 and COX-2.
  • COX-1 corresponds to the originally identified constitutive enzyme while COX-2 is rapidly and readily inducible by a number of agents including mitogens, endotoxin, hormones, cytokines and growth factors.
  • Prostaglandins generated by the action of COX have both physiological and pathological roles. It is generally believed that COX-1 is responsible for the important physiological functions such as maintenance of gastrointestinal integrity and renal blood flow.
  • the inducible form, COX-2 is believed to be responsible for the pathological effects of prostaglandins where rapid induction of the enzyme occurs in response to such agents as inflammatory agents, hormones, growth factors and cytokines.
  • a selective inhibitor of COX-2 would therefore have anti-inflammatory, anti-pyretic and analgesic properties, without the potential side effects associated with inhibition of COX-1.
  • WO 95/00501 discloses a range of mono and diaryl substituted monocyclic heterocycles useful in the treatment of COX-2 mediated diseases.
  • WO96/06840 discloses a range of mono and diaryl substituted 6,5 fused bicyclic heterocycles containing up to four non-contiguous heteroatoms, useful in the treatment of COX-2 mediated diseases.
  • WO96/21667 discloses a range of mono and diaryl substituted 5,5 fused bicyclic heterocycles useful in the treatment of COX-2 mediated diseases.
  • WO96/31509 discloses a range of diaryl substituted imidazo[1,2-a]pyridine derivatives useful in the treatment of COX-2 mediated diseases.
  • WO96/4164 (G.D. Searle & Co) relates to combinations of a COX-2 inhibitor and a leukotriene B 4 receptor antagonist and to their use for the treatment of inflammation and inflammation related disorders.
  • Talley J.J. Selective Inhibitors of cyclo-oxygenase-2
  • Expert Opinion on Therapeutic Patents vol 7 No. 1 January 1997, p55-62 contains a review of the COX-2 area and as such is cumulative to the prior art identified above.
  • pharmaceutically acceptable derivative is meant any pharmaceutically acceptable salt, solvate or ester, or salt or solvate of such ester, of the compounds of formula (I), or any other compound which upon administration to the recipient is capable of providing (directly or indirectly) a compound of formula (I) or an active metabolite or residue thereof.
  • salts referred to above will be the physiologically acceptable salts, but other salts may find use, for example in the preparation of compounds of formula (I) and the physiologically acceptable salts thereof.
  • Suitable pharmaceutically acceptable salts of the compounds of formula (I) include acid addition salts formed with inorganic or organic acids, preferably inorganic acids, e.g. hydrochlorides, hydrobromides and sulphates.
  • halogen is used to represent fluorine, chlorine, bromine or iodine.
  • alkyl' as a group or part of a group means a straight or branched chain alkyl group, for example a methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl or t-butyl group.
  • R 0 is at the 3- or 4-position of the phenyl ring, as defined in formula (I).
  • R 1 is at the 6-position of the pyridazine ring, as defined in formula (I).
  • R 0 is F, C 1-3 alkyl, C 1-3 alkoxy, C 1-3 alkoxy substituted by one or more fluorine atoms, or O(CH 2 ) 1-3 NR 4 R 5 . More preferably R 0 is F, C 1-3 alkoxy or C 1-3 alkoxy substituted by one or more fluorine atoms.
  • R 1 is C 1-4 alkylsulphonyl, C 1-4 alkoxy substituted by one or more fluorine atoms, O(CH 2 ) 1-3 CO 2 C 1-4 alkyl, O(CH 2 ) 1-3 SC 1-4 alkyl, (CH 2 ) 1-3 NR 4 R 5 , (CH 2 ) 1-3 SC 1-4 alkyl or C(O)NR 4 R 5 or, when R 0 is C 1-6 alkyl, C 1-6 alkoxy, O(CH 2 ) n NR 4 R 5 , may also be H.
  • R 1 is C 1-4 alkylsulphonyl, C 1-4 alkoxy substituted by one or more fluorine atoms or, when R 0 is C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkoxy substituted by one or more fluorine atoms, or O(CH 2 ) n NR 4 R 5 , may also be H.
  • R 2 is H.
  • R 3 is methyl or NH 2 .
  • R 4 and R 5 are independently C 1-3 alkyl or, together with the nitrogen atom to which they are attached, form a 5 - 6 membered saturated ring.
  • n is 1 - 3, more preferably 1 or 2.
  • R 0 is F, C 1-3 alkyl, C 1-3 alkoxy, C 1-3 alkoxy substituted by one or more fluorine atoms, or O(CH 2 ) n NR 4 R 5 ;
  • R 1 is C 1-4 alkylsulphonyl, C 1-4 alkoxy substituted by one or more fluorine atoms, O(CH 2 ) n CO 2 C 1-4 alkyl, O(CH 2 ) n SC 1-4 alkyl, (CH 2 ) n SC 1-4 alkyl, (CH 2 ) n SC 1-4 alkyl or C(O)NR 4 R 5 or, when R 0 is C 1-3 alkyl, C 1-3 alkoxy, C 1-3 alkoxy substituted by one or more fluorine atoms, or O(CH 2 ) n NR 4 R 5 , may also be H;
  • R 2 is H;
  • R 3 is methyl or NH 2
  • R 0 is F, methyl, C 1-2 alkoxy, OCHF 2 , or O(CH 2 ) n NR 4 R 5 ;
  • R 1 is methylsulphonyl, OCHF 2 , O(CH 2 ) n CO 2 C 1-4 alkyl, O(CH 2 ) n SCH 3 , (CH 2 ) n NR 4 R 5 , (CH 2 ) n SCH 3 or C(O)NR 4 R 5 or, when R 0 is methyl, C 1-2 alkoxy, OCHF 2 , or O(CH 2 ) n N(CH 3 ) 2 , may also be H;
  • R 2 is H;
  • R 3 is methyl or NH 2 ;
  • R 4 and R 5 are both methyl or, together with the nitrogen atom to which they are attached, form a 5 - 6 membered saturated ring; and
  • n is 1 - 2.
  • group A2 there is provided a further group of compounds (group A2) wherein R 0 is F, C 1-3 alkoxy or C 1-3 alkoxy substituted by one or more fluorine atoms; R 1 is C 1-4 alkylsulphonyl, C 1-4 alkoxy substituted by one or more fluorine atoms or, when R 0 C 1-3 alkoxy or C 1-3 alkoxy substituted by one or more fluorine atoms, may also be H; R 2 is H; and R 3 is methyl or NH 2 .
  • R 0 is preferably at the 3- or 4-position of the phenyl ring and R 2 is preferably at the 6-position of the pyridazine ring.
  • the present invention encompasses all isomers of the compounds of formula (I) and their pharmaceutically acceptable derivatives, including all geometric, tautomeric and optical forms, and mixtures thereof (e.g. racemic mixtures).
  • Particularly preferred compounds of the invention are:
  • Compounds of the invention are potent and selective inhibitors of COX-2. This activity is illustrated by their ability to selectively inhibit COX-2 over COX-1.
  • the compounds of the present invention are of interest for use in human and veterinary medicine, particularly in the treatment of the pain (both chronic and acute), fever and inflammation of a variety of conditions and diseases.
  • conditions and diseases are well known in the art and include rheumatic fever; symptoms associated with influenza or other viral infections, such as the common cold; lower back and neck pain; headache; toothache; sprains and strains; myositis; neuralgia; synovitis; arthritis, including rheumatoid arthritis; degenerative joint diseases, including osteoarthritis; gout and ankylosing spondylitis; tendinitis; bursitis; skin related conditions, such as psoriasis, eczema, burns and dermatitis; injuries, such as sports injuries and those arising from surgical and dental procedures.
  • the compounds of the invention may also be useful for the treatment of other conditions mediated by selective inhibition of COX-2.
  • the compounds of the invention may inhibit cellular and neoplastic transformation and metastatic tumour growth and hence be useful in the treatment of certain cancerous diseases, such as colonic cancer.
  • Compounds of the invention may also prevent neuronal injury by inhibiting the generation of neuronal free radicals (and hence oxidative stress) and therefore may be of use in the treatment of stroke; epilepsy; and epileptic seizures (including grand mal, petit mal, myoclonic epilepsy and partial seizures).
  • Compounds of the invention also inhibit prostanoid-induced smooth muscle contraction and hence may be of use in the treatment of dysmenorrhoea and premature labour.
  • Compounds of the invention inhibit inflammatory processes and therefore may be of use in the treatment of asthma, allergic rhinitis and respiratory distress syndrome; gastrointestinal conditions such as inflammatory bowel disease, Chron's disease, gastritis, irritable bowel syndrome and ulcerative colitis; and the inflammation in such diseases as vascular disease, migraine, periarteritis nodosa, thyroiditis, aplastic anemia, Hodgkin's disease, sclerodoma, type I diabetes, myasthenia gravis, multiple sclerosis, sorcoidosis, nephrotic syndrome, Bechet's syndrome, polymyositis, gingivitis, conjunctivitis and myocardial ischemia.
  • vascular disease migraine, periarteritis nodosa, thyroiditis, aplastic anemia, Hodgkin's disease, sclerodoma, type I diabetes, myasthenia gravis, multiple sclerosis, sorcoidosis, nephro
  • Compounds of the invention may also be useful in the treatment of ophthalmic diseases such as retinitis, retinopathies, uveitis and of acute injury to the eye tissue.
  • ophthalmic diseases such as retinitis, retinopathies, uveitis and of acute injury to the eye tissue.
  • Compounds of the invention may also be useful for the treatment of cognitive disorders such as dementia, particularly degenerative dementia (including senile dementia, Alzheimer's disease, Pick's disease, Huntington's chorea, Parkinson's disease and Creutzfeldt-Jakob disease), and vascular dementia (including multiinfarct dementia), as well as dementia associated with intracranial space occupying lesions, trauma, infections and related conditions (including HIV infection), metabolism, toxins, anoxia and vitamin deficiency; and mild cognitive impairment associated with ageing, particularly Age Associated Memory Impairment.
  • dementia particularly degenerative dementia (including senile dementia, Alzheimer's disease, Pick's disease, Huntington's chorea, Parkinson's disease and Creutzfeldt-Jakob disease), and vascular dementia (including multiinfarct dementia), as well as dementia associated with intracranial space occupying lesions, trauma, infections and related conditions (including HIV infection), metabolism, toxins, anoxia and vitamin deficiency; and mild cognitive impairment associated with ageing, particularly Age Associated
  • a method of treating a human or animal subject suffering from a condition which is mediated by selective inhibition of COX-2 comprises administering to said subject an effective amount of a compound of formula (I) or a pharmaceutically acceptable derivative.
  • a compound of formula (I) or a pharmaceutically acceptable derivative thereof for the manufacture of a therapeutic agent for the treatment of a condition which is mediated by selective inhibition of COX-2, such as an inflammatory disorder.
  • a method of treating a human or animal subject suffering from an inflammatory disorder comprises administering to said subject an effective amount of a compound of formula (I) or a pharmaceutically acceptable derivative thereof.
  • Suitable agents for adjunctive therapy include pain relievers such as a glycine antagonist, a sodium channel inhibitor (e.g. lamotrigine), a substance P antagonist (e.g. an NK 1 antagonist), acetaminophen or phenacetin; a matrix metalloproteinase inhibitor; a nitric oxide synthase (NOS) inhibitor (e.g. an iNOS or an nNOS inhibitor); an inhibitor of the release, or action, of tumour necrosis factor ⁇ ; an antibody therapy (e.g.
  • a stimulant including caffeine; an H 2 -antagonist, such as ranitidine; a proton pump inhibitor, such as omeprazole; an antacid, such as aluminium or magnesium hydroxide; an antiflatulent, such as simethicone; a decongestant, such as phenylephrine, phenylpropanolamine, pseudoephedrine, oxymetazoline, epinephrine, naphazoline, xylometazoline, propylhexedrine, or levo-desoxyephedrine; an antitussive, such as codeine, hydrocodone, carmiphen, carbetapentane, or dextramethorphan; a diuretic; or a sedating or non-sedating antihistamine.
  • a stimulant including caffeine
  • an H 2 -antagonist such as ranitidine
  • a proton pump inhibitor such as omeprazole
  • an antacid such as aluminium
  • compositions comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof adapted for use in human or veterinary medicine.
  • Such compositions may conveniently be presented for use in conventional manner in admixture with one or more physiologically acceptable carriers or excipients.
  • the compounds of formula (I) and their pharmaceutically acceptable derivatives may be formulated for administration in any suitable manner. They may, for example, be formulated for topical administration or administration by inhalation or, more preferably, for oral, transdermal or parenteral administration.
  • the pharmaceutical composition may be in a form such that it can effect controlled release of the compounds of formula (I) and their pharmaceutically acceptable derivatives.
  • the pharmaceutical composition may take the form of, for example, tablets (including sub-lingual tablets), capsules, powders, solutions, syrups or suspensions prepared by conventional means with acceptable excipients.
  • the pharmaceutical composition may be given in the form of a transdermal patch, such as a transdermal iontophoretic patch.
  • the pharmaceutical composition may be given as an injection or a continuous infusion (e.g. intravenously, intravascularly or subcutaneously).
  • the compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles and may contain formulatory agents such as suspending, stabilising and/or dispersing agents.
  • formulatory agents such as suspending, stabilising and/or dispersing agents.
  • For administration by injection these may take the form of a unit dose presentation or as a multidose presentation preferably with an added preservative.
  • the active ingredient may be in powder form for reconstitution with a suitable vehicle.
  • the compounds of the invention may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection.
  • the compounds of the invention may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
  • the compounds of the invention may also be used in combination with other therapeutic agents.
  • the invention thus provides, in a further aspect, a combination comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof together with a further therapeutic agent.
  • compositions comprising a combination as defined above together with a pharmaceutically acceptable carrier or excipient comprise a further aspect of the invention.
  • the individual components of such combinations may be administered either sequentially or simultaneously in separate or combined pharmaceutical formulations.
  • a proposed daily dosage of a compound of formula (I) for the treatment of man is 0.01mg/kg to 500mg/kg, such as 0.05mg/kg to 100mg/kg, e.g. 0.1mg/kg to 50mg/kg, which may be conveniently administered in 1 to 4 doses.
  • the precise dose employed will depend on the age and condition of the patient and on the route of administration. Thus, for example, a daily dose of 0.25mg/kg to 10mg/kg may be suitable for systemic administration.
  • R 0 to R 5 and n are as defined in formula (I) above unless otherwise stated;
  • Hal is a halogen, such as Br or I;
  • X is a counterion, such as I ; and alkyl is as previously defined.
  • compounds of formula (I) may be prepared by reacting a compound of formula (II) or a protected derivative thereof with a boronic acid of formula (III) or a suitable derivative thereof in the presence of a suitable transition metal catalyst.
  • Suitable derivatives of formula (III) include boronic acid esters, such as those described in R. Miyaura et al , J. Org. Chem., 1995, 60, 7508-7510.
  • the reaction is carried out in a solvent, such as an ether (e.g. 1,2 dimethoxyethane); in the presence of a base, such as an inorganic base (e.g. sodium carbonate); and employing a palladium catalyst, such as tetrakis(triphenylphosphine)palladium(0).
  • compounds of formula (I) wherein R 3 is C 1-6 alkyl may be prepared by oxidising a compound of formula (IV) or a protected derivative thereof under conventional conditions.
  • the oxidation is effected using a monopersulfate compound, such as potassium peroxymonosulfate (known as OxoneTM) and the reaction is carried out in a solvent, such as an aqueous alcohol, (e.g. aqueous methanol), and at between -78°C and ambient temperature.
  • a monopersulfate compound such as potassium peroxymonosulfate (known as OxoneTM)
  • a solvent such as an aqueous alcohol, (e.g. aqueous methanol), and at between -78°C and ambient temperature.
  • compounds of formula (I) wherein R 1 is C 1-6 alkylsulphonyl may be prepared by oxidising a compound of formula (V) or a protected derivative thereof under conventional conditions. Conveniently the oxidation is effected in the manner described just above for process (B).
  • compounds of formula (I) wherein R 1 is C 1-6 alkoxy substituted by one or more fluorine atoms may be prepared by reacting an alcohol of formula (VI) or a protected derivative thereof with a halofluoroalkane under conventional conditions.
  • a solvent such as a polar solvent (e.g. N,N -dimethylformamide)
  • a strong base such as an inorganic hydride (e.g. sodium hydride)
  • an inorganic hydride e.g. sodium hydride
  • compounds of formula (I) may be prepared by interconversion, utilising other compounds of formula (I) as precursors.
  • the following procedures are illustrative of suitable interconversions.
  • R 1 or R 2 represent C 1-6 alkyl substituted by one or more fluorine atoms
  • R 1 or R 2 represents C 1-6 alkyl substituted by one or more fluorine atoms
  • a suitable source of fluorine include, for example, diethylaminosulphur trifluoride.
  • the reaction is effected in the presence of a solvent, such as a halogenated hydrocarbon (e.g. dichloromethane), and at reduced temperature, such as -78°C.
  • a solvent such as a halogenated hydrocarbon (e.g. dichloromethane)
  • Suitable oxidising agents include, for example, manganese (IV) oxide. Conveniently the oxidation is effected in the presence of a solvent, such as a halogenated hydrocarbon (e.g. chloroform), and at elevated temperature (e.g. reflux).
  • a solvent such as a halogenated hydrocarbon (e.g. chloroform)
  • elevated temperature e.g. reflux
  • Compounds of formula (I) wherein R 1 or R 2 represent C 1-6 hydroxyalkyl, and wherein the hydroxy group is attached to the carbon linked to the pyridazine ring, may be prepared by reduction of the compound of formula (I) wherein R 1 or R 2 represent the corresponding aldehyde or ketone.
  • Suitable reducing agents include hydride reducing agents, such as diisobutylaluminium hydride. Conveniently the reduction is effected in the presence of a solvent, such as a halogenated hydrocarbon (e.g. dichloromethane), and at reduced temperature, such as -78°C.
  • Another process (F) for preparing compounds of formula (I) thus comprises deprotecting protected derivatives of compounds of formula (I).
  • the protecting groups used in the preparation of compounds of formula (I) may be used in conventional manner. See, for example, those described in 'Protective Groups in Organic Synthesis' by Theodora W. Greene and Peter G. M. Wuts, second edition, (John Wiley and Sons, 1991), which also describes methods for the removal of such groups.
  • esters of formula (VI) are first hydrolysed to their corresponding acids, for example by treatment with a strong base (e.g. sodium hydroxide), in the present of a solvent (e.g. ethanol) and at elevated temperature.
  • a strong base e.g. sodium hydroxide
  • a solvent e.g. ethanol
  • a halogenating agent conveniently at ambient temperature and in a solvent (e.g. chlorinated hydrocarbon), under which conditions the acid undergoes both halogenation and decarboxylation.
  • the halogenating agent is a brominating agent, such as bromine in the presence of a strong acid (e.g. hydrobromic acid in acetic acid) or N-bromosuccinimide, to yield the corresponding compound of formula (II) wherein Hal is bromine.
  • Esters of formula (VII) may be prepared by reacting a compound of formula (VIII) with an aminopyridazinium complex of formula (IX) under conventional conditions. Conveniently the reaction is effected in the presence of a base, such as potassium carbonate, a solvent, such as N,N -dimethylformamide and at ambient temperature.
  • a base such as potassium carbonate
  • a solvent such as N,N -dimethylformamide
  • Boronic acids of formula (III) are either known compounds or may be prepared by literature methods such as those described in, for example, EPA publication No. 533268.
  • compounds of the invention are isolated following work-up in the form of the free base.
  • Pharmaceutically acceptable acid addition salts of the compounds of the invention may be prepared using conventional means.
  • Solvates (e.g. hydrates) of a compound of the invention may be formed during the work-up procedure of one of the aforementioned process steps.
  • 1,8-Diazabicyclo[5.4.0]undec-7-ene (3.39ml) was added to a mixture of 3-(4-fluorophenyl)-prop-2-ynoic acid methyl ester (3.36g) and 1-amino-3-methoxypyridazin-1-ium mesitylene sulphonate 1 (6.1419g) in acetonitrile (125ml) and the mixture was stirred at ambient temperature for 48 hours. During the first 2 hours a stream of air was passed through the reaction.
  • Diazabicyclo[5.4.0]undec-7-ene (22.76ml, 2eq) was added dropwise to a solution of methyl 3-(4-methoxy-phenyl)-prop-2-ynoic acid 1 (14.46g, 76mM) and 1-amino pyridazinium iodide 2 (2eq) in acetonitrile under nitrogen and stirred for 6h. Purification by chromatography on silica gel eluting with toluene, then toluene:ethyl acetate (9:1) gave the title compound (2.76g) as a brown solid.
  • Solid t-butoxycarbonyl-O-mesitylenesulfonylhydroxylamine 1 (7.8g) was added portionwise with stirring to TFA (25ml) over 10min then stirred for a further 20 minutes. The solution was poured onto ice ( ⁇ 200ml) and left until the ice melted. The resulting white solid was filtered off, washed with water, and dissolved in DME (100ml). The solution was dried over 4A mol. sieves for 1.5 hours, filtered then added to a solution of 3-methylthio-pyridazine 2 (2.6g) in dichloromethane (35ml) and the reaction stirred at room temperature for 20h.
  • the intermediate salt was isolated by filtration as light brown crystals (3.87g), suspended in acetonitrile (100ml) and methyl 3-(4-fluoro-phenyl)-prop-2-ynoic acid (2.02g) added. 1,8-Diazabicyclo[5.4.0]undec-7-ene (2.1ml) was added dropwise and the reaction was stirred at room temperature for 20 hours. The resulting crystalline precipitate was filtered off, washed and dried (770mg). Concentration of the filtrate gave a second crop (430mg). The residues were partioned between water and ethyl acetate (100ml each) and the aqueous layer was extracted with ethyl acetate (20ml).
  • Diazabicyclo[5.4.0]undec-7-ene (1.47ml, 2eq) was added dropwise to a solution of methyl 3-(4-ethoxy-phenyl)-prop-2-ynoic acid (1.0g) and 1-amino pyridazinium iodide 2 (2.19g) in acetonitrile (10ml) under nitrogen and stirred for 5h. Concentration and aqueous workup gave the title compound (1.2g) as a sticky brown solid. MH + 298
  • the cooled reaction mixture was concentrated in vacuo and the residue suspended in 1,2 dimethoxyethane (10 ml), 2-(4-ethoxy-phenyl)-3-iodo-pyrazolo[1,5-b]pyridazine (0.4g) was added together with 2N sodium carbonate (4ml) and tetrakis(triphenylphosphine)palladium (0) (20mg) and the mixture heated at reflux under nitrogen for 18 hours.
  • the cooled reaction mixture was poured into water (60ml) and the suspension extracted with ethyl acetate (3x60ml). The organic extracts were combined, dried (Na 2 SO 4 ) and concentrated.
  • 1,8-Diazabicyclo[5.4.0]undec-7-ene (5ml) was added to a stirred, chilled, mixture of (3-fluoro-phenyl)-propynoic acid methyl ester (2.67g) and 1-amino-3-methoxypyridazin-1-ium mesitylene sulphonate (4.89g) in acetonitrile (80ml) and the mixture was stirred at 0° for 1hour then at ambient temperature for 18 hours. The mixture was concentrated in vacuo , and partitioned between ethyl acetate (150ml) and water (150ml). The aqueous phase was separated and further extracted with ethyl acetate (2x100ml).
  • N-bromo succinimide (195mg) was added to a solution of 6-difluoromethoxy-2-(3-fluoro-phenyl)-pyrazolo[1,5-b]pyridazine (251 mg) and sodium bicarbonate (185mg) in anhydrous DMF (10ml) and stirred for 18h.
  • the reaction mixture was diluted with ethyl acetate (300ml) and washed with water (10x20ml), brine (20ml), dried (Na 2 SO 4 ) and concentrated to give the title compound as a solid (293mg, 91%).
  • COS cells which had been stably transfected with cDNA for human COX-1 and human COX-2. 24 Hours prior to experiment, COS cells were transferred from the 175cm 2 flasks in which they were grown, onto 24-well cell culture plates using the following procedure.
  • the incubation medium (Dulbecco's modified eagles medium (DMEM) supplemented with heat-inactivated foetal calf serum (10%v/v), penicillin (100 IU/ml), streptomycin (100 ⁇ g/ml) and geneticin (600 ⁇ g/ml)) was removed from a flask of confluent cells (1 flask at confluency contains approximately 1x10 7 cells).
  • DMEM Dulbecco's modified eagles medium
  • the incubation medium was completely removed from the 24-well cell culture plates and replaced with 250 ⁇ l fresh DMEM (37°C).
  • the test compounds were made up to 250x the required test concentration in DMSO and were added to the wells in a volume of 1 ⁇ l. Plates were then mixed gently by swirling and then placed in an incubator for 1 hour (37°C, 95% air/5% CO 2 ). Following the incubation period, 10 ⁇ l of arachidonic acid (750 ⁇ M) was added to each well to give a final arachidonic acid concentration of 30 ⁇ M.
  • IC 50 value which is defined as the concentration of the compound required to inhibit the PGE2 release from the cells by 50%.
  • the selectivity ratio of inhibition of COX-1 versus COX-2 was calculated by comparing respective IC 50 values.
  • IC 50 values for inhibition of COX-2 and COX-1 were obtained for compounds of the invention:

Abstract

The invention provides the compounds of formula (I) and pharmaceutically acceptable derivatives thereof in which: R0 is halogen, C¿1-6?alkyl, C1-6alkoxy, C1-6alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR?4R5; R1 and R2¿ are independently selected from H, C¿1-6?alkyl, C1-6alkyl, substituted by one or more fluorine atoms, C1-6alkoxy, C1-6hydroxyalkyl, SC1-6alkyl, C(O)H, C(O)C1-6alkyl, C1-6alkylsulphonyl, C1-6alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C1-6alkyl, O(CH2)nSC1-6alkyl, (CH2)nNR?4R5, (CH¿2)nSC1-6alkyl or C(O)NR4R5; with the proviso that when R0 is at the 4-position and is halogen, at least one of R?1 and R2¿ is C¿1-6?alkylsulphonyl, C1-6alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C1-6alkyl, O(CH2)nSC1-6alkyl, (CH2)nNR?4R5¿ or (CH¿2?)nSC1-6alkyl, C(O)NR?4R5; R3¿ is C¿1-6?alkyl or NH2; R?4 and R5¿ are independently selected from H, or C¿1-6?alkyl or, together with the nitrogen atom to which they are attached, form a 4-8 membered saturated ring; and n is 1-4. Compounds of formula (I) are potent and selective inhibitors of COX-2 and are of use in the treatment of the pain, fever, inflammation of a variety of conditions and diseases.

Description

  • This invention relates to pyrazolo[1,5-b]pyridazine derivatives, to processes for their preparation, to pharmaceutical compositions containing them and to their use in medicine.
  • The enzyme cyclooxygenase (COX) has recently been discovered to exist in two isoforms, COX-1 and COX-2. COX-1 corresponds to the originally identified constitutive enzyme while COX-2 is rapidly and readily inducible by a number of agents including mitogens, endotoxin, hormones, cytokines and growth factors. Prostaglandins generated by the action of COX have both physiological and pathological roles. It is generally believed that COX-1 is responsible for the important physiological functions such as maintenance of gastrointestinal integrity and renal blood flow. In contrast the inducible form, COX-2, is believed to be responsible for the pathological effects of prostaglandins where rapid induction of the enzyme occurs in response to such agents as inflammatory agents, hormones, growth factors and cytokines. A selective inhibitor of COX-2 would therefore have anti-inflammatory, anti-pyretic and analgesic properties, without the potential side effects associated with inhibition of COX-1. We have now found a novel group of compounds which are both potent and selective inhibitors of COX-2.
  • WO 95/00501 (Merck Frosst Canada Inc) discloses a range of mono and diaryl substituted monocyclic heterocycles useful in the treatment of COX-2 mediated diseases. WO96/06840 (Merck Frosst Canada Inc) discloses a range of mono and diaryl substituted 6,5 fused bicyclic heterocycles containing up to four non-contiguous heteroatoms, useful in the treatment of COX-2 mediated diseases. WO96/21667 (Merck Frosst Canada Inc) discloses a range of mono and diaryl substituted 5,5 fused bicyclic heterocycles useful in the treatment of COX-2 mediated diseases. WO96/31509 (Glaxo Group Limited) discloses a range of diaryl substituted imidazo[1,2-a]pyridine derivatives useful in the treatment of COX-2 mediated diseases. WO96/4164 (G.D. Searle & Co) relates to combinations of a COX-2 inhibitor and a leukotriene B4 receptor antagonist and to their use for the treatment of inflammation and inflammation related disorders. Talley J.J. "Selective Inhibitors of cyclo-oxygenase-2", Expert Opinion on Therapeutic Patents vol 7 No. 1 January 1997, p55-62 contains a review of the COX-2 area and as such is cumulative to the prior art identified above.
  • The invention thus provides the compounds of formula (I)
    Figure 00020001
    and pharmaceutically acceptable derivatives thereof in which:
  • R0 is halogen, C1-6alkyl, C1-6alkoxy, C1-6alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR4R5;
  • R1 and R2 are independently selected from H, C1-6alkyl, C1-6alkyl substituted by one or more fluorine atoms, C1-6alkoxy, C1-6hydrnxyalkyl, SC1-6alkyl, C(O)H, C(O)C1-6alkyl, C1-6alkylsulphonyl, C1-6alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C1-6alkyl, O(CH2)nSC1-6alkyl, (CH2)nNR4R5, (CH2)nSC1-6alkyl or C(O)NR4R5; with the proviso that when R0 is at the 4-position and is halogen, at least one of R1 and R2 is C1-6alkylsulphonyl, C1-6alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C1-6alkyl, O(CH2)nSC1-6alkyl, (CH2)nNR4R5 or (CH2)nSC1-6alkyl, C(O)NR4R5;
  • R3 is C1-6alkyl or NH2;
  • R4 and R5 are independently selected from H, or C1-6alkyl or, together with the nitrogen atom to which they are attached, form a 4 - 8 membered saturated ring; and
  • n is 1-4.
  • By pharmaceutically acceptable derivative is meant any pharmaceutically acceptable salt, solvate or ester, or salt or solvate of such ester, of the compounds of formula (I), or any other compound which upon administration to the recipient is capable of providing (directly or indirectly) a compound of formula (I) or an active metabolite or residue thereof.
  • It will be appreciated that, for pharmaceutical use, the salts referred to above will be the physiologically acceptable salts, but other salts may find use, for example in the preparation of compounds of formula (I) and the physiologically acceptable salts thereof.
  • Suitable pharmaceutically acceptable salts of the compounds of formula (I) include acid addition salts formed with inorganic or organic acids, preferably inorganic acids, e.g. hydrochlorides, hydrobromides and sulphates.
  • The term halogen is used to represent fluorine, chlorine, bromine or iodine.
  • The term 'alkyl' as a group or part of a group means a straight or branched chain alkyl group, for example a methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl or t-butyl group.
  • Preferably, R0 is at the 3- or 4-position of the phenyl ring, as defined in formula (I).
  • Preferably, R1 is at the 6-position of the pyridazine ring, as defined in formula (I).
  • Preferably, R0 is F, C1-3alkyl, C1-3alkoxy, C1-3alkoxy substituted by one or more fluorine atoms, or O(CH2)1-3NR4R5. More preferably R0 is F, C1-3alkoxy or C1-3alkoxy substituted by one or more fluorine atoms.
  • Preferably, R1 is C1-4alkylsulphonyl, C1-4alkoxy substituted by one or more fluorine atoms, O(CH2)1-3CO2C1-4alkyl, O(CH2)1-3SC1-4alkyl, (CH2)1-3NR4R5, (CH2)1-3SC1-4alkyl or C(O)NR4R5 or, when R0 is C1-6alkyl, C1-6alkoxy, O(CH2)nNR4R5, may also be H. More preferably R1 is C1-4alkylsulphonyl, C1-4alkoxy substituted by one or more fluorine atoms or, when R0 is C1-6alkyl, C1-6alkoxy, C1-6alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR4R5, may also be H.
  • Preferably, R2 is H.
  • Preferably, R3 is methyl or NH2.
  • Preferably R4 and R5 are independently C1-3alkyl or, together with the nitrogen atom to which they are attached, form a 5 - 6 membered saturated ring.
  • Preferably, n is 1 - 3, more preferably 1 or 2.
  • Within the invention there is provided one group of compounds of formula (I) (group A) wherein: R0 is F, C1-3alkyl, C1-3alkoxy, C1-3alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR4R5; R1 is C1-4alkylsulphonyl, C1-4alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C1-4alkyl, O(CH2)nSC1-4alkyl, (CH2)nNR4R5, (CH2)nSC1-4alkyl or C(O)NR4R5 or, when R0 is C1-3alkyl, C1-3alkoxy, C1-3alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR4R5, may also be H; R2 is H; R3 is methyl or NH2; R4 and R5 are independently C1-3alkyl or, together with the nitrogen atom to which they are attached, form a 5 - 6 membered saturated ring; and n is 1 - 3.
  • Within group A, there is provided another group of compounds (group A1) wherein R0 is F, methyl, C1-2alkoxy, OCHF2, or O(CH2)nNR4R5; R1 is methylsulphonyl, OCHF2, O(CH2)nCO2C1-4alkyl, O(CH2)nSCH3, (CH2)nNR4R5, (CH2)nSCH3 or C(O)NR4R5 or, when R0 is methyl, C1-2alkoxy, OCHF2, or O(CH2)nN(CH3)2, may also be H; R2 is H; R3 is methyl or NH2; R4 and R5 are both methyl or, together with the nitrogen atom to which they are attached, form a 5 - 6 membered saturated ring; and n is 1 - 2.
  • Within group A, there is provided a further group of compounds (group A2) wherein R0 is F, C1-3alkoxy or C1-3alkoxy substituted by one or more fluorine atoms; R1 is C1-4alkylsulphonyl, C1-4alkoxy substituted by one or more fluorine atoms or, when R0 C1-3alkoxy or C1-3alkoxy substituted by one or more fluorine atoms, may also be H; R2 is H; and R3 is methyl or NH2.
  • Within groups A, A1 and A2, R0 is preferably at the 3- or 4-position of the phenyl ring and R2 is preferably at the 6-position of the pyridazine ring.
  • It is to be understood that the present invention encompasses all isomers of the compounds of formula (I) and their pharmaceutically acceptable derivatives, including all geometric, tautomeric and optical forms, and mixtures thereof (e.g. racemic mixtures).
  • Particularly preferred compounds of the invention are:
  • 3-(4-methanesulfonyl-phenyl)-2-(4-methoxy-phenyl)-pyrazolo[1,5-b]pyridazine;
  • 6-difluoromethoxy-2-(4-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine;
  • 2-(4-ethoxy-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine;
  • 2-(4-fluoro-phenyl)-6-methanesulfonyl-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine;
  • 2-(4-difluoromethoxy-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine;
  • 4-[2-(4-ethoxy-phenyl)-pyrazolo[1,5-b]pyridazin-3-yl]-benzenesulfonamide;
  • 6-difluoromethoxy-2-(3-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine;
    • and pharmaceutically acceptable derivatives thereof.
  • Compounds of the invention are potent and selective inhibitors of COX-2. This activity is illustrated by their ability to selectively inhibit COX-2 over COX-1.
  • In view of their selective COX-2 inhibitory activity, the compounds of the present invention are of interest for use in human and veterinary medicine, particularly in the treatment of the pain (both chronic and acute), fever and inflammation of a variety of conditions and diseases. Such conditions and diseases are well known in the art and include rheumatic fever; symptoms associated with influenza or other viral infections, such as the common cold; lower back and neck pain; headache; toothache; sprains and strains; myositis; neuralgia; synovitis; arthritis, including rheumatoid arthritis; degenerative joint diseases, including osteoarthritis; gout and ankylosing spondylitis; tendinitis; bursitis; skin related conditions, such as psoriasis, eczema, burns and dermatitis; injuries, such as sports injuries and those arising from surgical and dental procedures.
  • The compounds of the invention may also be useful for the treatment of other conditions mediated by selective inhibition of COX-2.
  • For example, the compounds of the invention may inhibit cellular and neoplastic transformation and metastatic tumour growth and hence be useful in the treatment of certain cancerous diseases, such as colonic cancer.
  • Compounds of the invention may also prevent neuronal injury by inhibiting the generation of neuronal free radicals (and hence oxidative stress) and therefore may be of use in the treatment of stroke; epilepsy; and epileptic seizures (including grand mal, petit mal, myoclonic epilepsy and partial seizures).
  • Compounds of the invention also inhibit prostanoid-induced smooth muscle contraction and hence may be of use in the treatment of dysmenorrhoea and premature labour.
  • Compounds of the invention inhibit inflammatory processes and therefore may be of use in the treatment of asthma, allergic rhinitis and respiratory distress syndrome; gastrointestinal conditions such as inflammatory bowel disease, Chron's disease, gastritis, irritable bowel syndrome and ulcerative colitis; and the inflammation in such diseases as vascular disease, migraine, periarteritis nodosa, thyroiditis, aplastic anemia, Hodgkin's disease, sclerodoma, type I diabetes, myasthenia gravis, multiple sclerosis, sorcoidosis, nephrotic syndrome, Bechet's syndrome, polymyositis, gingivitis, conjunctivitis and myocardial ischemia.
  • Compounds of the invention may also be useful in the treatment of ophthalmic diseases such as retinitis, retinopathies, uveitis and of acute injury to the eye tissue.
  • Compounds of the invention may also be useful for the treatment of cognitive disorders such as dementia, particularly degenerative dementia (including senile dementia, Alzheimer's disease, Pick's disease, Huntington's chorea, Parkinson's disease and Creutzfeldt-Jakob disease), and vascular dementia (including multiinfarct dementia), as well as dementia associated with intracranial space occupying lesions, trauma, infections and related conditions (including HIV infection), metabolism, toxins, anoxia and vitamin deficiency; and mild cognitive impairment associated with ageing, particularly Age Associated Memory Impairment.
  • According to a further aspect of the invention, we provide a compound of formula (I) or a pharmaceutically acceptable derivative thereof for use in human or veterinary medicine.
  • According to another aspect of the invention, we provide a compound of formula (I) or a pharmaceutically acceptable derivative thereof for use in the treatment of a condition which is mediated by selective inhibition of COX-2.
  • According to a further aspect of the invention, we provide a method of treating a human or animal subject suffering from a condition which is mediated by selective inhibition of COX-2 which comprises administering to said subject an effective amount of a compound of formula (I) or a pharmaceutically acceptable derivative.
  • According to another aspect of the invention, we provide the use of a compound of formula (I) or a pharmaceutically acceptable derivative thereof for the manufacture of a therapeutic agent for the treatment of a condition which is mediated by selective inhibition of COX-2, such as an inflammatory disorder.
  • According to a further aspect of the invention, we provide a method of treating a human or animal subject suffering from an inflammatory disorder, which method comprises administering to said subject an effective amount of a compound of formula (I) or a pharmaceutically acceptable derivative thereof.
  • It is to be understood that reference to treatment includes both treatment of established symptoms and prophylactic treatment, unless explicitly stated otherwise.
  • It will be appreciated that the compounds of the invention may advantageously be used in conjunction with one or more other therapeutic agents. Examples of suitable agents for adjunctive therapy include pain relievers such as a glycine antagonist, a sodium channel inhibitor (e.g. lamotrigine), a substance P antagonist (e.g. an NK1 antagonist), acetaminophen or phenacetin; a matrix metalloproteinase inhibitor; a nitric oxide synthase (NOS) inhibitor (e.g. an iNOS or an nNOS inhibitor); an inhibitor of the release, or action, of tumour necrosis factor α; an antibody therapy (e.g. a monoclonal antibody therapy); a stimulant, including caffeine; an H2-antagonist, such as ranitidine; a proton pump inhibitor, such as omeprazole; an antacid, such as aluminium or magnesium hydroxide; an antiflatulent, such as simethicone; a decongestant, such as phenylephrine, phenylpropanolamine, pseudoephedrine, oxymetazoline, epinephrine, naphazoline, xylometazoline, propylhexedrine, or levo-desoxyephedrine; an antitussive, such as codeine, hydrocodone, carmiphen, carbetapentane, or dextramethorphan; a diuretic; or a sedating or non-sedating antihistamine. It is to be understood that the present invention covers the use of a compound of formula (I) or a pharmaceutically acceptable derivative thereof in combination with one or more other therapeutic agents.
  • The compounds of formula (I) and their pharmaceutically acceptable derivatives are conveniently administered in the form of pharmaceutical compositions. Thus, in another aspect of the invention, we provide a pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof adapted for use in human or veterinary medicine. Such compositions may conveniently be presented for use in conventional manner in admixture with one or more physiologically acceptable carriers or excipients.
  • The compounds of formula (I) and their pharmaceutically acceptable derivatives may be formulated for administration in any suitable manner. They may, for example, be formulated for topical administration or administration by inhalation or, more preferably, for oral, transdermal or parenteral administration. The pharmaceutical composition may be in a form such that it can effect controlled release of the compounds of formula (I) and their pharmaceutically acceptable derivatives.
  • For oral administration, the pharmaceutical composition may take the form of, for example, tablets (including sub-lingual tablets), capsules, powders, solutions, syrups or suspensions prepared by conventional means with acceptable excipients.
  • For transdermal administration, the pharmaceutical composition may be given in the form of a transdermal patch, such as a transdermal iontophoretic patch.
  • For parenteral administration, the pharmaceutical composition may be given as an injection or a continuous infusion (e.g. intravenously, intravascularly or subcutaneously). The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles and may contain formulatory agents such as suspending, stabilising and/or dispersing agents. For administration by injection these may take the form of a unit dose presentation or as a multidose presentation preferably with an added preservative.
  • Alternatively for parenteral administration the active ingredient may be in powder form for reconstitution with a suitable vehicle.
  • The compounds of the invention may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds of the invention may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
  • As stated above, the compounds of the invention may also be used in combination with other therapeutic agents. The invention thus provides, in a further aspect, a combination comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof together with a further therapeutic agent.
  • The combinations referred to above may conveniently be presented for use in the form of a pharmaceutical formulation and thus pharmaceutical formulations comprising a combination as defined above together with a pharmaceutically acceptable carrier or excipient comprise a further aspect of the invention. The individual components of such combinations may be administered either sequentially or simultaneously in separate or combined pharmaceutical formulations.
  • When a compound of formula (I) or a pharmaceutically acceptable derivative thereof is used in combination with a second therapeutic agent active against the same disease state the dose of each compound may differ from that when the compound is used alone. Appropriate doses will be readily appreciated by those skilled in the art.
  • A proposed daily dosage of a compound of formula (I) for the treatment of man is 0.01mg/kg to 500mg/kg, such as 0.05mg/kg to 100mg/kg, e.g. 0.1mg/kg to 50mg/kg, which may be conveniently administered in 1 to 4 doses. The precise dose employed will depend on the age and condition of the patient and on the route of administration. Thus, for example, a daily dose of 0.25mg/kg to 10mg/kg may be suitable for systemic administration.
  • Compounds of formula (I) and pharmaceutically acceptable derivatives thereof may be prepared by any method known in the art for the preparation of compounds of analogous structure.
  • Suitable methods for the preparation of compounds of formula (I) and pharmaceutically acceptable derivatives thereof are described below. In the formulae that follow R0 to R5 and n are as defined in formula (I) above unless otherwise stated; Hal is a halogen, such as Br or I; X is a counterion, such as I ; and alkyl is as previously defined.
  • Thus according to a first process (A), compounds of formula (I) may be prepared by reacting a compound of formula (II)
    Figure 00100001
    or a protected derivative thereof with a boronic acid of formula (III)
    Figure 00100002
    or a suitable derivative thereof in the presence of a suitable transition metal catalyst. Suitable derivatives of formula (III) include boronic acid esters, such as those described in R. Miyaura et al, J. Org. Chem., 1995, 60, 7508-7510. Conveniently, the reaction is carried out in a solvent, such as an ether (e.g. 1,2 dimethoxyethane); in the presence of a base, such as an inorganic base (e.g. sodium carbonate); and employing a palladium catalyst, such as tetrakis(triphenylphosphine)palladium(0).
  • According to a another process (B), compounds of formula (I) wherein R3 is C1-6alkyl may be prepared by oxidising a compound of formula (IV)
    Figure 00100003
    or a protected derivative thereof under conventional conditions. Conveniently the oxidation is effected using a monopersulfate compound, such as potassium peroxymonosulfate (known as Oxone™) and the reaction is carried out in a solvent, such as an aqueous alcohol, (e.g. aqueous methanol), and at between -78°C and ambient temperature.
  • According to a another process (C), compounds of formula (I) wherein R1 is C1-6alkylsulphonyl may be prepared by oxidising a compound of formula (V)
    Figure 00110001
    or a protected derivative thereof under conventional conditions. Conveniently the oxidation is effected in the manner described just above for process (B).
  • According to a another process (D), compounds of formula (I) wherein R1 is C1-6alkoxy substituted by one or more fluorine atoms may be prepared by reacting an alcohol of formula (VI)
    Figure 00110002
    or a protected derivative thereof with a halofluoroalkane under conventional conditions. Conveniently the reaction is effected in a solvent, such as a polar solvent (e.g. N,N-dimethylformamide), in the presence of a strong base, such as an inorganic hydride (e.g. sodium hydride), at about ambient temperature and using the appropriate bromofluoroalkane to give the desired compound of formula (I).
  • According to another process (E) compounds of formula (I) may be prepared by interconversion, utilising other compounds of formula (I) as precursors. The following procedures are illustrative of suitable interconversions.
  • Compounds of formula (I) wherein R1 or R2 represent C1-6alkyl substituted by one or more fluorine atoms may be prepared from the appropriate compound of formula (I) wherein R1 or R2 is C1-6hydroxyalkyl, C(O)H or C(O)C1-6alkyl, by treatment with a suitable source of fluorine. Suitable sources of fluorine include, for example, diethylaminosulphur trifluoride. Conveniently the reaction is effected in the presence of a solvent, such as a halogenated hydrocarbon (e.g. dichloromethane), and at reduced temperature, such as -78°C.
  • Compounds of formula (I) wherein R1 or R2 represent C(O)H may be prepared from the corresponding compound of formula (I) wherein R1 or R2 represent CH2OH by oxidation. Suitable oxidising agents include, for example, manganese (IV) oxide. Conveniently the oxidation is effected in the presence of a solvent, such as a halogenated hydrocarbon (e.g. chloroform), and at elevated temperature (e.g. reflux).
  • Compounds of formula (I) wherein R1 or R2 represent C1-6hydroxyalkyl, and wherein the hydroxy group is attached to the carbon linked to the pyridazine ring, may be prepared by reduction of the compound of formula (I) wherein R1 or R2 represent the corresponding aldehyde or ketone. Suitable reducing agents include hydride reducing agents, such as diisobutylaluminium hydride. Conveniently the reduction is effected in the presence of a solvent, such as a halogenated hydrocarbon (e.g. dichloromethane), and at reduced temperature, such as -78°C.
  • As will be appreciated by those skilled in the art it may be necessary or desirable at any stage in the synthesis of compounds of formula (I) to protect one or more sensitive groups in the molecule so as to prevent undesirable side reactions.
  • Another process (F) for preparing compounds of formula (I) thus comprises deprotecting protected derivatives of compounds of formula (I).
  • The protecting groups used in the preparation of compounds of formula (I) may be used in conventional manner. See, for example, those described in 'Protective Groups in Organic Synthesis' by Theodora W. Greene and Peter G. M. Wuts, second edition, (John Wiley and Sons, 1991), which also describes methods for the removal of such groups.
  • Compounds of formula (II) may be prepared by halogenating compounds of formula (VII)
    Figure 00130001
    by conventional means.
  • Thus esters of formula (VI) are first hydrolysed to their corresponding acids, for example by treatment with a strong base (e.g. sodium hydroxide), in the present of a solvent (e.g. ethanol) and at elevated temperature. The corresponding acid is then treated with a halogenating agent, conveniently at ambient temperature and in a solvent (e.g. chlorinated hydrocarbon), under which conditions the acid undergoes both halogenation and decarboxylation. Conveniently, the halogenating agent is a brominating agent, such as bromine in the presence of a strong acid (e.g. hydrobromic acid in acetic acid) or N-bromosuccinimide, to yield the corresponding compound of formula (II) wherein Hal is bromine.
  • Esters of formula (VII) may be prepared by reacting a compound of formula (VIII)
    Figure 00130002
    with an aminopyridazinium complex of formula (IX)
    Figure 00140001
    under conventional conditions. Conveniently the reaction is effected in the presence of a base, such as potassium carbonate, a solvent, such as N,N-dimethylformamide and at ambient temperature.
  • Boronic acids of formula (III) are either known compounds or may be prepared by literature methods such as those described in, for example, EPA publication No. 533268.
  • Compounds of formulae (IV), (V) and (VI) may be prepared by methods analogous to those described for the preparation of the compound of formula (I) from compounds of formula (II).
  • Compounds of formula (VIII) are either known compounds or may be prepared by literature methods such as those described in, for example, D H Wadsworth et al, J Org Chem, (1987), 52(16), 3662-8 and J.Morris and D.G.Wishka, Synthesis (1994), (1), 43-6.
  • Compounds of formula (IX) are either known compounds or may be prepared by literature methods such as those described in, for example, Y Kobayashi et al, Chem Pharm Bull, (1971), 19(10), 2106-15; T. Tsuchiya, J. Kurita and K. Takayama, Chem. Pharm. Bull. 28(9) 2676-2681 (1980) and K Novitskii et al, Khim Geterotskil Soedin, 1970 2, 57-62.
  • Certain intermediates described above are novel compounds, and it is to be understood that all novel intermediates herein form further aspects of the present invention. Compounds of formula (II) are key intermediates and represent a particular aspect of the present invention.
  • Conveniently, compounds of the invention are isolated following work-up in the form of the free base. Pharmaceutically acceptable acid addition salts of the compounds of the invention may be prepared using conventional means.
  • Solvates (e.g. hydrates) of a compound of the invention may be formed during the work-up procedure of one of the aforementioned process steps.
  • The following Examples illustrate the invention but do not limit the invention in any way. All temperatures are in 0C. Flash column chromatography was carried out using Merck 9385 silica. Thin layer chromatography (Tlc) was carried out on silica plates. NMR was carried out on a Brucker 250MHz spectrometer. Chemical shifts are given, with respect to tetramethylsilane as internal chemical shift reference, in δ ppm. The following abbreviations are used: Me = methyl, s = singlet, d = doublet, t = triplet and m = multiplet.
    • Example 1 6-Difluoromethoxy-2-(4-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine (i) 6-Methoxy-2-(4-fluoro-phenyl-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester.
  • 1,8-Diazabicyclo[5.4.0]undec-7-ene (3.39ml) was added to a mixture of 3-(4-fluorophenyl)-prop-2-ynoic acid methyl ester (3.36g) and 1-amino-3-methoxypyridazin-1-ium mesitylene sulphonate1 (6.1419g) in acetonitrile (125ml) and the mixture was stirred at ambient temperature for 48 hours. During the first 2 hours a stream of air was passed through the reaction. The mixture was concentrated in vacuo, dissolved in ethyl acetate (150ml), washed with water (3 x 25ml), dried (MgSO4), filtered and evaporated in vacuo to give the title compound as a brown solid (4.77g).
    1H NMR (CDCl3): 8.4 (d, 1H, J=10Hz) 7.85-7.90 (m, 2H) 7.1-7.2 (m, 2H) 6.9-7.0 (d, 1H, J=10Hz) 4.1 (s, 3H) 3.9 (s, 3H)
    MH+ 302
    Ref:1 T. Tsuchiya, J. Kurita and K. Takayama, Chem. Pharm. Bull. 28(9) 2676-2681 (1980).
    • (ii) 6-Methoxy-2-(4-fluoro-phenyl-pyrazolo[1,5-b]pyridazine-3-carboxylic acid
  • A mixture of 6-methoxy-2-(4-fluoro-phenyl-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester (4.469g), 2N sodium hydroxide (50ml) and methanol (90ml) was heated at reflux for 2 hours. The cooled solution was added to 2N hydrochloric acid (200ml) and the title compound was isolated by filtration as a beige solid (3.639g).
    1H NMR (DMSO-d6): 12.8 (br. s, 1H) 8.4 (d, 1H, J=10Hz) 7.8-7.9 (m, 2H) 7.21-7.32 (m, 2H) 7.15-7.2 (d, 1H, J=10Hz) 4.0 (s, 3H)
    MH+ 288
    • (iii) 2-(4-Fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine
  • A mixture of 6-methoxy-2-(4-fluoro-phenyl-pyrazolo[1,5-b]pyridazine-3-carboxylic acid (869mg) and sodium bicarbonate (756mg) in dimethylformamide (10ml) was treated with N-bromosuccinimide (587mg) and stirred at ambient temperature for 1 hour, then added to water (50ml) and extracted with ethyl acetate (3x50ml), dried (MgSO4), and evaporated in vacuo. The resulting brown solid (1.612g) was dissolved in 1,2 dimethoxyethane (20ml). 2N Aqueous sodium carbonate solution (10ml) was added together with 4-(methanesulphonyl)phenyl boronic acid (660mg) and tetrakis(triphenylphosphine)palladium (0) (100mg) and the mixture was heated at reflux for 20 hours. The reaction was poured into water(50ml), extracted with dichloromethane (3x100ml). The combined organic extracts were dried (MgSO4) and evaporated in vacuo to give a brown solid (1.116g) which was purified by flash column chromatography on silica, eluting with cyclohexane/ethyl acetate (4:1 then 2:1), to give the title compound as a yellow solid (390mg).
    Tlc, SiO2, Rf 0.3 (1:1 cyclohexane/ethyl acetate), detection UV
    MH+ 398
    • (iv) 2-(4-Fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazin-6-ol
  • A mixture of 2-(4-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-6-methoxypyrazolo[1,5-b]pyridazine (321 mg) and pyridine hydrochloride (1.4g) was heated to and at 200°C in a sealed vessel (Reactivial™) for 3 hours. The cooled reaction was poured into water (20ml), and extracted with ethyl acetate (3x30ml). The combined organic extracts dried (MgSO4), filtered and evaporated in vacuo to give a solid which was triturated with diethyl ether to give the title compound as a beige solid (119mg).
    Tlc, SiO2, Rf 0.07 (1:2 cyclohexane/ethyl acetate), detection UV.
    MH+ 384
    • (v) 6-Difluoromethoxy-2-(4-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine
  • A solution of 2-(4-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazin-6-ol (0.2 g) in anhydrous dimethyl formamide (5 ml) was treated with sodium hydride ( 0.046g, 60% dispersion in mineral oil), after effervescence ceased a stream of bromodifluoromethane gas was passed through the mixture at ambient temperature for 30 minutes. The reaction mixture was then poured into water (50 ml) and extracted with ethyl acetate (50 ml), the organic extract was washed with water (3X 50 ml), dried and concentrated in vacuo. The residue was purified by chromatography to give the title compound as a white solid (0.17g).
    MH+ = 434
    1HNMR(CDCl3):δ8.05-8.0(d,J=10HZ,2H)8.0-7.95(d,J=10HZ,1H)7.6-7.5(m,4H)7.8-7.2(t,J=70HZ,1H)7.1-7.05(t,J=11 HZ,2H)6.9-6.85(d,J=10HZ,1H)3.15(s,3H)
    Tlc,SiO2,Rf 0.35(ethyl acetate/cyclohexane(1/1))
    • Example 2 3-(4-Methanesulfonyl-phenyl)-2-(4-methoxy-phenyl)-pyrazolo[1,5-b]pyridazine (i) 2-(4-Methoxy-phenyl)-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester
  • Diazabicyclo[5.4.0]undec-7-ene (22.76ml, 2eq) was added dropwise to a solution of methyl 3-(4-methoxy-phenyl)-prop-2-ynoic acid1 (14.46g, 76mM) and 1-amino pyridazinium iodide2 (2eq) in acetonitrile under nitrogen and stirred for 6h. Purification by chromatography on silica gel eluting with toluene, then toluene:ethyl acetate (9:1) gave the title compound (2.76g) as a brown solid.
    MH+ 284
    1H NMR (CDCl3) δ 3.87 (3H, s) 3.9 (3H, s) 7.0 (2H, d, J=9Hz) 7.25 (1H, dd, J= 9 & 4Hz) 7.90 (2H, d, J = 9Hz) 8.45 (1 H, dd, J=4 & 2Hz) 8.55 (1 H, dd, J=9 & 2 Hz)
    Ref: 1 J.Morris and D.G.Wishka, Synthesis (1994), (1), 43-6
    Ref: 2 Kobayashi et al Chem.Pharm.Bull. (1971), 19 (10), 2106-15
    • (ii) 3-(4-Methanesulfonyl-phenyl)-2-(4-methoxy-phenyl)-pyrazolo[1,5-b]pyridazine
  • A mixture of 2-(4-methoxy-phenyl)-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester (2.76g) and aq. sodium hydroxide (2N, 30ml) in ethanol (30ml) was refluxed under nitrogen for 2h. The cooled mixture was acidified with hydrochloric acid (2N) and the resulting white solid (2.53g) isolated by filtration. This solid was dissolved in DMF and sodium bicarbonate (2.67g, 3.3eq) added, followed by N-bromosuccinimide (1.88g, 1.1eq) portionwise. After stirring for 1h under nitrogen, water was added and extracted into ethyl acetate (2x 25ml).
  • The dried organic phase was concentrated and the residue taken up in DME (60ml). Aqueous sodium carbonate (2N, 15ml) was added, followed by 4-methanesulfonyl-phenylboronic acid (3.12g) and tetrakis(triphenylphosphine)palladium(0) (250mg). The mixture was heated at reflux under nitrogen for 18h, cooled, poured into water and extracted into ethyl acetate (2 x 25ml). The combined organic phases were dried and concentrated onto silica gel. Chromatography on silica gel eluting with toluene:ethyl acetate (8:1) gave, on concentration, the title compound (3.58g) as a cream solid.
    MH+ 380
    1H NMR (DMSO) δ 3.25 (3H, s) 3.75 (3H, s) 6.95 (2H, d, J= 8.5 Hz) 7.25 (1H, dd, J = 9 & 5Hz) 7.45 (2H, d, J= 8.5Hz) 7.60 (2H, d, J= 8Hz) 7.9 (2H, d, J= 8.5 Hz) 8.15 (1H, dd, J = 9&2Hz) 8.49 (1H, dd, J= 5&2Hz)
    • Example 3 2-(4-Ethoxy-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine (i) 4-[3-(4-Methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazin-2-yl]-phenol
  • Boron tribromide (1M solution in CH2Cl2, 2.1 eq) was added to 3-(4-methanesulfonyl-phenyl)-2-(4-methoxy-phenyl)-pyrazolo[1,5-b]pyridazine (3.58g) in CH2Cl2 at -70°. The mixture was stirred for 10min then warmed to 0° and stirred at 0° overnight. The reaction mixture was made alkaline with potassium carbonate then acidified with hydrochloric acid (2M), poured into water and extracted into CH2Cl2. The organic phase was dried, filtered and concentrated to give the title compound (1.87g) as a yellow solid.
    MH+ 366
    1H NMR (DMSO) δ 3.30 (3H, s) 6.80 (2H, d, J= 8.5 Hz) 7.30 (1H, dd, J = 9 & 5Hz) 7.35 (2H, d, J= 8.5Hz) 7.60 (2H, d, J= 8Hz) 8.0 (2H, d, J= 8.5 Hz) 8.20 (1H, dd, J = 9& 2Hz) 8.55 (1H, dd, J = 5& 2Hz) 9.75 (1H, s)
    • (ii) 2-(4-Ethoxy-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine
  • 4-[3-(4-Methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazin-2-yl]-phenol (663mg, 1.82), iodoethane (1eq) and potassium carbonate (2eq) in acetonitrile (30ml) were heated at reflux under nitrogen for 18h. The cooled reaction mixture was partitioned between water (30ml) and ethyl acetate (30 ml). The organic phase was collected, dried and purified by chromatography to give the title compound (547mg) as a cream foam.
    MH+ 394
    1H NMR (DMSO) δ 1.45 (3H, t, J=7Hz) 3.10 (3H, s) 4.1 (2H, q, J=7Hz) 6.87 (2H, d, J= 9 Hz) 7.08 (1H, dd, J = 9 & 5Hz) 7.55 (4H, t, J= 9Hz) 7.92 (1H, dd, J= 9 &2 Hz) 7.95 (2H, d, J= 9 Hz) 8.20 (1H, dd, J = 9& 2Hz) 8.32 (1H, dd, J = 5& 2Hz)
    • Example 4 2-(4-Fluoro-phenyl)-6-methanesulfonyl-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine (i) 2-(4-Fluoro-phenyl)-6-methylsulfanyl-pyrazolol[1,5-b]pyridazine-3-carboxylic acid methyl ester
  • Solid t-butoxycarbonyl-O-mesitylenesulfonylhydroxylamine1 (7.8g) was added portionwise with stirring to TFA (25ml) over 10min then stirred for a further 20 minutes. The solution was poured onto ice (∼200ml) and left until the ice melted. The resulting white solid was filtered off, washed with water, and dissolved in DME (100ml). The solution was dried over 4A mol. sieves for 1.5 hours, filtered then added to a solution of 3-methylthio-pyridazine2 (2.6g) in dichloromethane (35ml) and the reaction stirred at room temperature for 20h. The intermediate salt was isolated by filtration as light brown crystals (3.87g), suspended in acetonitrile (100ml) and methyl 3-(4-fluoro-phenyl)-prop-2-ynoic acid (2.02g) added. 1,8-Diazabicyclo[5.4.0]undec-7-ene (2.1ml) was added dropwise and the reaction was stirred at room temperature for 20 hours. The resulting crystalline precipitate was filtered off, washed and dried (770mg). Concentration of the filtrate gave a second crop (430mg). The residues were partioned between water and ethyl acetate (100ml each) and the aqueous layer was extracted with ethyl acetate (20ml). The combined organics were washed with water, brine and dried. Removal of solvent gave a brown oil which was purified by flash chromatography on silica (300g) eluting with cyclohexane / ethyl acetate (3:1) to give a further quantity of product (247mg). The three crops were combined to give the title compound (1.45g) as a light brown solid.
    MH+ 318
    1H NMR (CDCl3) δ 2.70 (3H, s ), 3.88 (3H, s) 7.08-7.18 (3H, m) 7.84 (2H, m) 8.31 (1H, d, J = 10Hz)
    Ref: 1K Novitskii et al, Khim Geterotskil Soedin, 1970 2, 57-62
    Ref: 2 Barlin G. B., Brown, W. V., J Chem Soc (1968), (12), 1435-45
    • (ii) 2-(4-Fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-6-methylsulfanyl-pyrazolo[1,5-b]pyridazine
  • A mixture of the 2-(4-fluoro-phenyl)-6-(methylthio)-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester (1.45g) potassium carbonate (690mg) in methanol (40ml) and water (14ml) was stirred and heated under reflux for 20 hours under nitrogen. The solvents were removed and the resulting solid partioned between ethyl acetate (50ml) and water (250ml). The aqueous layer was acidified to pH1 (2MHCI) and a solid was filtered off (1.0g, MH+ 304). A mixture of the solid (1.0g), sodium bicarbonate (557mg) and NBS (594mg) were stirred at room temperature for 4 hours. The reaction was poured into water (150ml) and extracted with ethyl acetate (3x50ml). The combined extracts were washed with water (50ml), brine (20ml), dried and concentrated. The resulting solid (1.015g, MH+ 338,340), 4-(methanesulphonyl)phenyl boronic acid (902mg), sodium carbonate (740mg) and tetrakis(triphenylphosphine)palladium(0) (175mg) were stirred and heated under nitrogen at reflux in DME (30mls) and water (15ml) for 48 hours. The reaction was poured into water and extracted with ethyl acetate (3x50ml). The combined extracts were dried and the solvent removed to give a brown solid. This was purified on silica (300g) eluting with cyclohexane, ethyl acetate (1:1) to give the title compound (0.713g) as a yellow solid.
    MH+ 414
    1H NMR δ (DMSO) 2.65 (3H, s) 3.28 (3H, s) 7.20 -7.30 (3H, m) 7.55 (2H, m) 7.62 (4H, d, J = 8.5Hz) 7.95-8.05 (3H, m)
    • (iii) 2-(4-Fluoro-phenyl)-6-methanesulfonyl-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine
  • A suspension of 2-(4-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-6-(methylthio)-pyrazolo[1,5-b]pyridazine (60mg 0.145) in MeOH (5ml) and water (2ml) was stirred with oxone (196mg 0.32) for 20 hours. The resulting solution was poured into water (50ml) and extracted with chloroform (3x20ml). The combined extracts were dried and the solvent removed. Crystallisation of the residue from methanol gave the title compound (60mg) as a white solid.
    MH+ 446
    1H NMR (DMSO-d6) δ 3.34 (3H, s) 3.53 (3H, s) 7.33 (2H, t, J = 9Hz) 7.62 (2H, m) 7.68 (1H, d, J = 8.5Hz) 8.04 (1H, d, J= 10Hz) 8.52 (1H, d, J = 9Hz)
    TLC SiO2 Hexane:Ethyl acetate (1:1) Rf 0.24 UV
    • Example 5 2-(4-Difluoromethoxy-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine
  • Sodium hydride (48mg, 60% disp. in oil, 1.2mmol) was added to a solution of 4-[3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazin-2-yl]-phenol (200mg, 0.55mmol) in anhydrous dimethylformamide (5ml). Bromodifluoromethane gas was gently bubbled through the solution for 20min, then diluted with CH2Cl2 (30ml). Aqueous workup followed by chromatography on silica gel with CH2Cl2:ethyl acetate (3:1) as eluant then chromatography with CH2Cl2:ethyl acetate (10:1) as eluant gave the title compound (63mg, 28%) as a white solid.
    MH+ 416
    NMR (CDCl3) δ 8.38 (1H,dd, J=4Hz), 8.01 (2H, d, J = 8.5Hz), 7.94 (1H, dd, J= 9 & 2Hz), 7.65 (2H, d, J 8.5 Hz) 7.57 (2H, d, J = 8Hz), 7.10 (3H, m), 6.87 - 6.27 (1H, t, J= 7.4Hz) 3.15 (3H, s)
    • Example 6 4-[2-(4-Ethoxy-phenyl)-pyrazolo[1,5-b]pyridazin-3-yl]-benzenesulfonamide (i) 2-(4-Ethoxy-phenyl)-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester
  • Diazabicyclo[5.4.0]undec-7-ene (1.47ml, 2eq) was added dropwise to a solution of methyl 3-(4-ethoxy-phenyl)-prop-2-ynoic acid (1.0g) and 1-amino pyridazinium iodide2 (2.19g) in acetonitrile (10ml) under nitrogen and stirred for 5h. Concentration and aqueous workup gave the title compound (1.2g) as a sticky brown solid.
    MH+ 298
    • (ii) 2-(4-Ethoxy-phenyl)-pyrazolo[1,5-b]pyridazine-3-carboxylic acid
  • A mixture of 2-(4-ethoxy-phenyl)-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester (1.2g), ethanol (10ml) and 2N sodium hydroxide (10ml) was heated to 80° for 1.5h. The mixture was allowed to cool and acidified to pH 1 with 2N hydrochloric acid. The title compound was isolated by filtration as a brown solid (716mg, 63%).
    MH+ 284
    • (iii) 2-(4-Ethoxy-phenyl)-3-iodo-pyrazolo[1,5-b]pyridazine
  • A mixture of 2-(4-ethoxy-phenyl)-pyrazolo[1,5-b]pyridazine-3-carboxylic acid (710mg), N-iodosuccinimide (678mg) and sodium bicarbonate (717mg) in DMF (8ml) was stirred for 4h. A further quantity of N-iodosuccinimide(100mg) was added and stirring continued for 2h. Aqueous workup gave a dark brown solid which was purified by SPE with dichloromethane as eluant. This gave the title compound as an orange-brown solid (429mg, 47%).
    MH+ 366
    • (iv) 4-[2-(4-Ethoxy-phenyl)-pyrazolol[1,5-b]pyridazin-3-yl]-benzenesulfonamide
  • A mixture of 4-iodobenzenesulphonamide ( 0.311g), dipinacoldiborane1 (0.279g), potassium acetate (486mg) and [1,1'-bis(diphenylphosphino)-ferrocene]palladium(II) chloride complex with dichloromethane (1:1) (0.45g) in dimethylformamide (8ml) was heated under nitrogen at 80° for 2 h. The cooled reaction mixture was concentrated in vacuo and the residue suspended in 1,2 dimethoxyethane (10 ml), 2-(4-ethoxy-phenyl)-3-iodo-pyrazolo[1,5-b]pyridazine (0.4g) was added together with 2N sodium carbonate (4ml) and tetrakis(triphenylphosphine)palladium (0) (20mg) and the mixture heated at reflux under nitrogen for 18 hours. The cooled reaction mixture was poured into water (60ml) and the suspension extracted with ethyl acetate (3x60ml). The organic extracts were combined, dried (Na2SO4) and concentrated. The residue was purified by chromatography eluting with dichloromethane/ethyl acetate (3:1) to give the title compound as a yellow solid (0.116g, 27%).
    MH+ 395
    NMR (CDCL3) δ 8.32 (1H, dd, J=4 & 2Hz), 7.97 (2H, d, J=8Hz), 7.89 (1H, dd, J=9 & 2Hz), 7.54 (4H, m), 7.04 (1H, dd, J=9 & 4Hz), 6.88 (2H, d, J=9Hz), 1.43 (3H, t, J=7 Hz)
    Ref: 1R. Miyaura et al J.Org.Chem.,1995,60,7508-7510.
    • Example 7 6-Difluoromethoxy-2-(3-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine (i) 1-(2,2-Dibromo-vinyl)-3-fluoro-benzene
  • To a stirred cooled (ice/salt, 0°) solution of carbon tetrabromide (48.82g) in anhydrous CH2Cl2 (200ml) was added portionwise over 3 minutes, triphenylphosphine (77.1g), maintaining the temperature below 10°. The resulting orange suspension was stirred at 0° for 1 hour before adding to it , 3-fluorobenzaldehyde (7.8ml). After the addition was complete, the suspension was stirred at 0° for 1 hour then quenched by the addition of water (75ml). The organic phase was separated and washed with brine (75ml), dried (Na2SO4) and evaporated to dryness. The residual gum was poured into cyclohexane (1L) and stirred for 30 minutes. The organic phase was decanted and the residue taken up into CH2Cl2 and poured into cyclohexane (1 L). This procedure was repeated twice more and the combined organic phases concentrated to ∼100ml and passed through silica gel. The filtrate was concentrated to give the title compound as a mobile yellow oil (24g, 100%).
    MH+ 280, MH- 279
    NMR (CDCl3) δ 7.05 (1H, tm, J= 9Hz) 7.3 (3H, m ) 7.45 (1H, s)
    • (ii) (3-Fluoro-phenyl)-propynoic acid methyl ester
  • To a stirred solution of 1-(2,2-dibromo-vinyl)-3-fluoro-benzene (23.8g) in anhydrous THF (350ml) cooled to -78° was added dropwise over 30 minutes, n-butyllithium (2.2eq, 1.6M in hexanes). The mixture was stirred for a further 30 minutes at -78° before methyl chloroformate (11.6g, 9.5ml) was added and the resultant mixture allowed to warm to 0° for 1hour before being diluted with 1:1 saturated aqueous sodium bicarbonate:ammonium chloride (100ml) and extracted into ether (2x 100ml). The combined organic extract was washed with brine (25ml). dried (Na2SO4) and evaporated to dryness to give the title compound as a brown oil (16.7g, 100%).
    MH- 173
    NMR (CDCl3) δ 7.4-7.1 (4H, m) 3.85 (3H, s, CO2Me)
    • (iii) 2-(3-Fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester
  • 1,8-Diazabicyclo[5.4.0]undec-7-ene (5ml) was added to a stirred, chilled, mixture of (3-fluoro-phenyl)-propynoic acid methyl ester (2.67g) and 1-amino-3-methoxypyridazin-1-ium mesitylene sulphonate (4.89g) in acetonitrile (80ml) and the mixture was stirred at 0° for 1hour then at ambient temperature for 18 hours. The mixture was concentrated in vacuo, and partitioned between ethyl acetate (150ml) and water (150ml). The aqueous phase was separated and further extracted with ethyl acetate (2x100ml). The combined organic extracts were washed with water (2 x 50ml), brine (25ml), dried (MgSO4), filtered and evaporated in vacuo to give a solid which was triturated with anhydrous ether: petroleum ether (1:0.5) to give the title compound as a brown solid (2.4g, 53%).
    MH+ 302
    1H NMR (CDCl3) δ 12.8 (1H, br s); 8.4 (1H, d, J 10Hz) 7.7-7.6 (2H, m) 7.42 (1H, q, J 8 Hz) 7.15 (1H, td, J 8 & 3Hz) 6.95 (1H, d, J 10Hz) 4.1 (3H, s) 3.88 (3H, s)
    • (iv) 2-(3-Fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic acid
  • 2N sodium hydroxide (50ml) was added to a solution of 2-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester (2.3g) in absolute ethanol (50ml) and the resulting mixture heated to reflux for three hours. The cooled reaction mixture was poured slowly into a stirred solution of 2N hydrochloric acid (300ml). The resulting suspension was stirred at ambient temperature for 1 hour then filtered and the filter cake washed with water and dried in vacuo at 60° to give the title compound as an off-white solid (2.0g, 91%).
    MH+ 288
    1H NMR (DMSO) δ 8.45 (1H, d, J 10Hz); 7.67 (2H, m); 7.5 (1H, q, J 7Hz); 7.3 (1H, td, J 7& 2Hz); 7.21 (1H, d, J 10Hz); 4.0 (3H, s)
    • (v) 3-Bromo-2-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine
  • To a stirred solution of 2-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic acid (2.0g) in anhydrous DMF (20ml) was added n-bromosuccinimide (1.78g) and the resulting solution stirred at ambient temperature for 3 hours. The reaction mixture was diluted with ethyl acetate (800ml) and washed sequentially with water (10x100ml) and sat. brine (25ml), dried (Na2SO4), and concentrated to give the title compound as a buff solid (2.1g, 93%).
    MH+ 323, MH- 321
    1H NMR (CDCl3) 7.9 (2H, m) 7.8 (1H, d, J 10Hz); 7.45 (1H, m); 7.1 91H, td, J 8 & 2 Hz); 6.78 (1H, d, J 10Hz); 4.1 (3H, s)
    • (vi) 6-Difluoromethoxy-2-(3-fluoro-phenyl)-pyrazolo[1,5-b]pyridazine
  • Portions of 3-bromo-2-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine (400mg, 2.1g total) were placed in individual Reactivials equipped with a magnetic stirrer bar. Pyridine hydrochloride (10eq) was added to each vial, the vials sealed, and heated to 200° for 3 hours. The vials were allowed to cool to ∼140° before opening and the contents poured into ice/water. The resulting mixture was extracted into ethyl acetate (3x100ml) and the combined organic extracts washed with water (7x75ml), dried (Na2SO4) and evaporated to give the des-bromo phenol as a brown solid (1.0g, MH+ 230). This solid was dissolved in anhydrous DMF (10ml) and sodium hydride (60% dispersion in mineral oil, 200mg) added portionwise. After stirring for 20 minutes at ambient temperature the solution was transferred to a small cooled autoclave and bromodifluoromethane (5ml, xs, condensed at -30°) added. The autoclave was then sealed, allowed to warm to ambient temperature and stirred for 36 hours. The resulting solution was diluted with ethyl acetate (200ml), washed with water (10x20ml), dried (Na2SO4), concentrated and the residual gum purified by flash column chromatography with cyclohexane:ethyl acetate (4:1) as eluant. This gave the title compound as a solid (652mg, 60%).
    MH+ 280 MH- 278
    NMR (DMSO) δ 8.42(1H, d, J= 10Hz) 7.85 (1H, d, J 8Hz) 7.78 (1H, t, J 70Hz) 7.55 (1H, q, J 8Hz) 7.38 (1H, s) 7.25 (1H, m) 7.17 (1H, d, J 10Hz)
    • (vii) 3-Bromo-6-difluoromethoxy-2-(3-fluoro-phenyl)-pyrazolo[1,5-b]pyridazine
  • N-bromo succinimide (195mg) was added to a solution of 6-difluoromethoxy-2-(3-fluoro-phenyl)-pyrazolo[1,5-b]pyridazine (251 mg) and sodium bicarbonate (185mg) in anhydrous DMF (10ml) and stirred for 18h. The reaction mixture was diluted with ethyl acetate (300ml) and washed with water (10x20ml), brine (20ml), dried (Na2SO4) and concentrated to give the title compound as a solid (293mg, 91%).
    MH+ 359, MH- 356/357
    NMR (DMSO) 6 8.36 (1H, d, J 10Hz) 7.88 (1H, d, J 8Hz) 7.78 (1H, t, J 70Hz, OCHF2) 7.77 (1H, dm, J 10Hz) 7.62 (1H, dt, J 8 & 6Hz) 7.38 (1H, dt, J 9 & 2Hz) 7.3 (1H, d, J 10Hz)
    • (viii) 6-Difluoromethoxy-2-(3-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine
  • To a stirred solution of 3-bromo-6-difluoromethoxy-2-(3-fluoro-phenyl)-pyrazolo[1,5-b]pyridazine (286mg) in DMF(20ml) was added 2N aq sodium carbonate (10ml). To this mixture was added 4-methanesulfonyl-phenylboronic acid (180mg) and tetrakis triphenylphosphine palladium (0) (34mg). The resulting mixture was stirred and heated to reflux for 18 hours. The cooled reaction mixture was diluted with ethyl acetate (300ml) and the organic solution washed with water (10x30ml) and brine (30ml), dried (Na2SO4) and evaporated to give a gum which was purified by flash column chromatography with chloroform:ethyl acetate (50:1 to 5:1) as eluant. Combination of appropriate fractions and concentration gave the title compound as an off-white solid (132mg, 37%).
    MH+ 434
    1H NMR( CDCl3) δ 8.02 (1H, d, J 9Hz); 7.95 (2H, d, J 10Hz); 7.58 (1H, d, 9Hz); 7.52 (1H, t, J 70Hz); 7.32 (3H, m); 7.08 (1H, m); 6.9 (1H, d, J 9Hz); 3.15 (3H, s)
    • Biological Data
  • Inhibitory activity against human COX-1 and COX-2 was assessed in COS cells which had been stably transfected with cDNA for human COX-1 and human COX-2. 24 Hours prior to experiment, COS cells were transferred from the 175cm2 flasks in which they were grown, onto 24-well cell culture plates using the following procedure. The incubation medium (Dulbecco's modified eagles medium (DMEM) supplemented with heat-inactivated foetal calf serum (10%v/v), penicillin (100 IU/ml), streptomycin (100µg/ml) and geneticin (600µg/ml)) was removed from a flask of confluent cells (1 flask at confluency contains approximately 1x107 cells). 10ml of phosphate buffered saline (PBS) was added to the flask to wash the cells. Having discarded the PBS, cells were then rinsed in 10ml trypsin for 20 seconds, after which the trypsin was removed and the flask placed in an incubator (37°) for 1-2 minutes until cells became detached from the flask. The flask was then removed from the incubator and cells resuspended in 10ml of fresh incubation medium. The contents of the flask was transferred to a 250ml sterile container and the volume of incubation medium subsequently made up to 100ml. 1ml cell suspension was pipetted into each well of 4x24-well cell culture plates. The plates were then placed in an incubator (37°C, 95% air/5% CO2) overnight. If more than 1 flask of cells were required, the cells from the individual flasks were combined before being dispensed into the 24-well plates.
  • Following the overnight incubation, the incubation medium was completely removed from the 24-well cell culture plates and replaced with 250µl fresh DMEM (37°C). The test compounds were made up to 250x the required test concentration in DMSO and were added to the wells in a volume of 1µl. Plates were then mixed gently by swirling and then placed in an incubator for 1 hour (37°C, 95% air/5% CO2). Following the incubation period, 10µl of arachidonic acid (750µM) was added to each well to give a final arachidonic acid concentration of 30µM. Plates were then incubated for a further 15 minutes, after which the incubation medium was removed from each well of the plates and stored at -20°C, prior to determination of prostaglandin E2 (PGE2) levels using enzyme immunoassay. The inhibitory potency of the test compound was expressed as an IC50 value, which is defined as the concentration of the compound required to inhibit the PGE2 release from the cells by 50%. The selectivity ratio of inhibition of COX-1 versus COX-2 was calculated by comparing respective IC50 values.
  • The following IC50 values for inhibition of COX-2 and COX-1 were obtained for compounds of the invention:
    Example No. COX-2: IC50(nM) COX-1: IC50(nM)
    1(v) 35 >100,000
    2(ii) <10 3,880
    3(ii) 3 >100,000
    4(iii) 370 >100,000
    5 21 >100,000
    6(iv) 0.44 3828
    7(viii) 16 >55,200

Claims (12)

  1. Compounds of formula (I)
    Figure 00280001
    and pharmaceutically acceptable derivatives thereof in which:
    R0 is halogen, C1-6alkyl, C1-6alkoxy, C1-6alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR4R5;
    R1 and R2 are independently selected from H, C1-6alkyl, C1-6alkyl substituted by one or more fluorine atoms, C1-6alkoxy, C1-6hydroxyalkyl, SC1-6alkyl, C(O)H, C(O)C1-6alkyl, C1-6alkylsulphonyl, C1-6alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C1-6alkyl, O(CH2)nSC1-6alkyl, (CH2)nNR4R5, (CH2)nSC1-6alkyl or C(O)NR4R5; with the proviso that when R0 is at the 4-position and is halogen, at least one of R1 and R2 is C1-6alkylsulphonyl, C1-6alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C1-6alkyl, O(CH2)nSC1-6alkyl, (CH2)nNR4R5 or (CH2)nSC1-6alkyl, C(O)NR4R5;
    R3 is C1-6alkyl or NH2;
    R4 and R5 are independently selected from H, or C1-6alkyl or, together with the nitrogen atom to which they are attached, form a 4 - 8 membered saturated ring; and
    n is 1-4.
  2. Compounds as claimed in claim 1 wherein R0 is F, C1-3alkyl, C1-3alkoxy, C1-3alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR4R5; R1 is C1-4alkylsulphonyl, C1-4alkoxy substituted by one or more fluorine atoms, O(CH2)nCO2C1-4alkyl, O(CH2)nSC1-4alkyl, (CH2)nNR4R5, (CH2)nSC1-4alkyl or C(O)NR4R5 or, when R0 is C1-3alkyl, C1-3alkoxy, C1-3alkoxy substituted by one or more fluorine atoms, or O(CH2)nNR4R5, may also be H; R2 is H; R3 is methyl or NH2; R4 and R5 are independently C1-3alkyl or, together with the nitrogen atom to which they are attached, form a 5 - 6 membered saturated ring; and n is 1 - 3.
  3. Compounds as claimed in claim 1 or 2 wherein R0 is F, methyl, C1-2alkoxy, OCHF2, or O(CH2)nNR4R5; R1 is methylsulphonyl, OCHF2, O(CH2)nCO2C1-4alkyl, O(CH2)nSCH3, (CH2)nNR4R5, (CH2)nSCH3 or C(O)NR4R5 or, when R0 is methyl, C1-2alkoxy, OCHF2, or O(CH2)nN(CH3)2, may also be H; R2 is H; R3 is methyl or NH2; R4 and R5 are both methyl or, together with the nitrogen atom to which they are attached, form a 5 - 6 membered saturated ring; and n is 1 - 2.
  4. Compounds as claimed in claim 1 or 2 wherein R0 is F, C1-3alkoxy or C1-3alkoxy substituted by one or more fluorine atoms; R1 is C1-4alkylsulphonyl, C1-4alkoxy substituted by one or more fluorine atoms or, when R0 C1-3alkoxy or C1-3alkoxy substituted by one or more fluorine atoms, may also be H; R2 is H; and R3 is methyl or NH2.
  5. Compounds as claimed in any one of claims 1 to 4 wherein R0 is at the 3- or 4-position of the phenyl ring.
  6. Compounds as claimed in any one of claims 1 to 5 wherein R1 is at the 6- position of the pyridazine ring.
  7. Compounds as claimed in any one of claims 1 to 6 wherein the compound is 2-(4-ethoxy-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine or 6-difluoromethoxy-2-(3-fluoro-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine;
    and pharmaceutically acceptable derivatives thereof.
  8. A process for the preparation of compound of formula (I) and pharmaceutically acceptable derivatives thereof as defined in any one of claims 1 to 7, which comprises:
    (A) reacting a compound of formula (II)
    Figure 00300001
    or a protected derivative thereof, with a compound of formula (III)
    Figure 00300002
    or a protected derivative thereof; or
    (B) where R3 represents C1-6alkyl, reacting a compound of formula (IV)
    Figure 00300003
    or a protected derivative thereof with an oxidising agent; or
    (C) where R1 is C1-6alkylsulphonyl, oxidising a compound of formula (V)
    Figure 00300004
    or a protected derivative.
    (D) where R1 is C1-6alkoxy substituted by one or more fluorine atoms, reacting a alcohol of formula (VI)
    Figure 00310001
    or a protected derivative thereof with a halofluoroalkane.
    (E) interconversion of a compound of formula (I) into another compound of formula (I); or
    (F) deprotecting a protected derivative of compound of formula (I);
    and optionally converting compounds of formula (I) prepared by any one of processes (A) to (F) into pharmaceutically acceptable derivatives thereof.
  9. A pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof as defined in any one of Claims 1 to 7 in admixture with one or more physiologically acceptable carriers or excipients.
  10. A compound of formula (I) or a pharmaceutically acceptable derivative thereof as defined in any one of Claims 1 to 7 for use in human or veterinary medicine.
  11. The use of a compound of formula (I) or a pharmaceutically acceptable derivative thereof as defined in any one of Claims 1 to 7 for the manufacture of a therapeutic agent for the treatment of chronic and acute pain, fever, inflammation, cellular and neoplastic transformation, metastatic tumour growth, neuronal injury, prostanoid-induced smooth muscle contraction, ophthalmic diseases and cognitive disorders.
  12. The use of a compond of formula (I) or a pharmaceutically acceptable derivative thereof as claimed in claim 11 for the treatment of inflammation.
EP98947502A 1997-09-05 1998-09-03 2,3-diaryl-pyrazolo(1,5-b)pyridazines derivatives, their preparation and their use as cyclooxygenase 2 (cox-2) inhibitors Expired - Lifetime EP1032575B1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP04025990A EP1510519B1 (en) 1997-09-05 1998-09-03 Pharmaceutical compositions comprising 2,3-diarylpyrazolo[1,5-B]pyridazine derivatives
EP03077298A EP1369421B1 (en) 1997-09-05 1998-09-03 Pharmaceutical compositions comprising 2,3-Diaryl-pyrazolo[1,5-B]pyridazine derivatives
SI9830528T SI1032575T1 (en) 1997-09-05 1998-09-03 2,3-diaryl-pyrazolo(1,5-b)pyridazines derivatives, their preparation and their use as cyclooxygenase 2 (cox-2) inhibitors

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
GBGB9718792.6A GB9718792D0 (en) 1997-09-05 1997-09-05 Chemical compounds
GB9718792 1997-09-05
GBGB9727116.7A GB9727116D0 (en) 1997-12-23 1997-12-23 Chemical compounds
GB9727116 1997-12-23
PCT/EP1998/005558 WO1999012930A1 (en) 1997-09-05 1998-09-03 2,3-diaryl-pyrazolo[1,5-b]pyridazines derivatives, their prepa ration and their use as cyclooxygenase 2 (cox-2) inhibitors

Related Child Applications (1)

Application Number Title Priority Date Filing Date
EP03077298A Division EP1369421B1 (en) 1997-09-05 1998-09-03 Pharmaceutical compositions comprising 2,3-Diaryl-pyrazolo[1,5-B]pyridazine derivatives

Publications (2)

Publication Number Publication Date
EP1032575A1 EP1032575A1 (en) 2000-09-06
EP1032575B1 true EP1032575B1 (en) 2003-07-23

Family

ID=26312181

Family Applications (3)

Application Number Title Priority Date Filing Date
EP04025990A Expired - Lifetime EP1510519B1 (en) 1997-09-05 1998-09-03 Pharmaceutical compositions comprising 2,3-diarylpyrazolo[1,5-B]pyridazine derivatives
EP98947502A Expired - Lifetime EP1032575B1 (en) 1997-09-05 1998-09-03 2,3-diaryl-pyrazolo(1,5-b)pyridazines derivatives, their preparation and their use as cyclooxygenase 2 (cox-2) inhibitors
EP03077298A Expired - Lifetime EP1369421B1 (en) 1997-09-05 1998-09-03 Pharmaceutical compositions comprising 2,3-Diaryl-pyrazolo[1,5-B]pyridazine derivatives

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP04025990A Expired - Lifetime EP1510519B1 (en) 1997-09-05 1998-09-03 Pharmaceutical compositions comprising 2,3-diarylpyrazolo[1,5-B]pyridazine derivatives

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP03077298A Expired - Lifetime EP1369421B1 (en) 1997-09-05 1998-09-03 Pharmaceutical compositions comprising 2,3-Diaryl-pyrazolo[1,5-B]pyridazine derivatives

Country Status (28)

Country Link
US (4) US6451794B1 (en)
EP (3) EP1510519B1 (en)
KR (1) KR100382619B1 (en)
CN (1) CN1155600C (en)
AP (1) AP1354A (en)
AT (3) ATE245649T1 (en)
AU (1) AU744997B2 (en)
BG (1) BG64420B1 (en)
BR (1) BR9812046A (en)
CA (1) CA2303152A1 (en)
DE (3) DE69816651T2 (en)
DK (1) DK1032575T3 (en)
EA (1) EA002775B1 (en)
EE (1) EE04617B1 (en)
ES (3) ES2231757T3 (en)
HR (1) HRP20000122B1 (en)
HU (1) HUP0003644A3 (en)
IL (1) IL134688A (en)
IS (1) IS5389A (en)
NO (1) NO315559B1 (en)
NZ (1) NZ502985A (en)
PL (1) PL194557B1 (en)
PT (1) PT1032575E (en)
SK (1) SK283922B6 (en)
TR (1) TR200000595T2 (en)
TW (1) TW570922B (en)
WO (1) WO1999012930A1 (en)
YU (1) YU11900A (en)

Families Citing this family (82)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100382619B1 (en) 1997-09-05 2003-05-09 글락소 그룹 리미티드 2,3-Diaryl-Pyrazolo[1,5-B]Pyridazines Derivatives, Their Preparation and Their Use As Cyclooxygenase 2(COX-2) Inhibitors
ES2228127T3 (en) * 1998-11-03 2005-04-01 Glaxo Group Limited DERIVATIVES OF PIRAZOLOPIRIDINE AS SELECTIVE COH-2 INHIBITORS.
US6833373B1 (en) 1998-12-23 2004-12-21 G.D. Searle & Co. Method of using an integrin antagonist and one or more antineoplastic agents as a combination therapy in the treatment of neoplasia
WO2000052008A1 (en) 1999-02-27 2000-09-08 Glaxo Group Limited Pyrazolopyridines
GB9929039D0 (en) * 1999-12-08 2000-02-02 Glaxo Group Ltd Medicaments
GB9930358D0 (en) * 1999-12-22 2000-02-09 Glaxo Group Ltd Process for the preparation of chemical compounds
NZ519781A (en) 1999-12-23 2004-04-30 Nitromed Inc Nitrosated and nitrosylated cyclooxygenase-2 inhibitors, compositions and methods of use
GB0002312D0 (en) * 2000-02-01 2000-03-22 Glaxo Group Ltd Medicaments
CZ302448B6 (en) 2000-07-20 2011-05-25 Lauras As Pharmaceutical composition
PE20020506A1 (en) 2000-08-22 2002-07-09 Glaxo Group Ltd PIRAZOLE DERIVATIVES FUSED AS PROTEIN KINASE INHIBITORS
GB0021494D0 (en) * 2000-09-01 2000-10-18 Glaxo Group Ltd Chemical comkpounds
GB0025449D0 (en) * 2000-10-17 2000-11-29 Glaxo Group Ltd Chemical compounds
US7163940B2 (en) 2000-12-15 2007-01-16 Smithkline Beecham Corporation Pyrazolopyridinyl pyrimidine therapeutic compounds
WO2002048147A2 (en) 2000-12-15 2002-06-20 Glaxo Group Limited Pyrazolopyridines
ES2227451T3 (en) 2001-03-08 2005-04-01 Smithkline Beecham Corporation DERIVATIVES OF PIRAZOLOPIRIDINE.
US7034030B2 (en) 2001-03-30 2006-04-25 Smithkline Beecham Corporation Pyralopyridines, process for their preparation and use as therapeutic compounds
JP4219171B2 (en) 2001-04-10 2009-02-04 スミスクライン ビーチャム コーポレーション Antiviral pyrazolopyridine compounds
US6962914B2 (en) 2001-04-27 2005-11-08 Smithkline Beecham Corporation Pyrazolopyridinyl pyridine and pyrimidine therapeutic compounds
US6756498B2 (en) 2001-04-27 2004-06-29 Smithkline Beecham Corporation Process for the preparation of chemical compounds
GB0112802D0 (en) * 2001-05-25 2001-07-18 Glaxo Group Ltd Pyrimidine derivatives
GB0112810D0 (en) * 2001-05-25 2001-07-18 Glaxo Group Ltd Pyrimidine derivatives
WO2003000689A1 (en) 2001-06-21 2003-01-03 Smithkline Beecham Corporation Imidazo`1,2-a!pyridine derivatives for the prophylaxis and treatment of herpes viral infections
WO2003031446A1 (en) 2001-10-05 2003-04-17 Smithkline Beecham Corporation Imidazo-pyridine derivatives for use in the treatment of herpes viral infection
GB0124934D0 (en) * 2001-10-17 2001-12-05 Glaxo Group Ltd Chemical compounds
GB0124938D0 (en) 2001-10-17 2001-12-05 Glaxo Group Ltd Chemical compounds
GB0124939D0 (en) * 2001-10-17 2001-12-05 Glaxo Group Ltd Chemical compounds
GB0124941D0 (en) * 2001-10-17 2001-12-05 Glaxo Group Ltd Chemical compounds
GB0124936D0 (en) * 2001-10-17 2001-12-05 Glaxo Group Ltd Chemical compounds
GB0124933D0 (en) * 2001-10-17 2001-12-05 Glaxo Group Ltd Chemical compounds
GB0124932D0 (en) * 2001-10-17 2001-12-05 Glaxo Group Ltd Chemical compounds
GB0124931D0 (en) * 2001-10-17 2001-12-05 Glaxo Group Ltd Chemical compounds
ES2292839T3 (en) 2001-12-11 2008-03-16 Smithkline Beecham Corporation DERIVATIVES OF PIRAZOLO-PIRIDINA AS AGENTS AGAINST HERPES.
EP1463730B1 (en) * 2001-12-17 2006-04-19 SmithKline Beecham Corporation Pyrazolopyridazine derivatives
KR100840907B1 (en) * 2001-12-28 2008-06-24 씨제이제일제당 (주) Bipyridinyl derivatives as a highly selective cyclooxygenase-2 inhibitor
KR100686537B1 (en) 2001-12-28 2007-02-27 씨제이 주식회사 Diaryl 1,2,4-triazole derivatives as a highly selective cyclooxygenase-2 inhibitor
DE60316913T2 (en) * 2002-02-12 2008-11-20 Smithkline Beecham Corp. NICOTINAMIDES AND THEIR USE AS P38 INHIBITORS
GB0206200D0 (en) * 2002-03-15 2002-05-01 Glaxo Group Ltd Pharmaceutical compositions
GB0217757D0 (en) 2002-07-31 2002-09-11 Glaxo Group Ltd Novel compounds
ATE325115T1 (en) 2002-08-19 2006-06-15 Glaxo Group Ltd PYRIMIDINE DERIVATIVES AS SELECTIVE COX-2 INHIBITORS
UY27939A1 (en) 2002-08-21 2004-03-31 Glaxo Group Ltd COMPOUNDS
GB0221443D0 (en) 2002-09-16 2002-10-23 Glaxo Group Ltd Pyridine derivates
AU2003275266A1 (en) 2002-10-03 2004-05-04 Smithkline Beecham Corporation Therapeutic compounds based on pyrazolopyridine derivatives
US20040147581A1 (en) * 2002-11-18 2004-07-29 Pharmacia Corporation Method of using a Cox-2 inhibitor and a 5-HT1A receptor modulator as a combination therapy
GB0227443D0 (en) * 2002-11-25 2002-12-31 Glaxo Group Ltd Pyrimidine derivatives
ES2214130B1 (en) * 2003-02-13 2005-12-01 Almirall Prodesfarma, S.A. 2-3'-BIPIRIDINES.
ES2213485B1 (en) * 2003-02-13 2005-12-16 Almirall Prodesfarma, S.A. DERIVATIVES OF 2-FENILPIRAN-4-ONA.
ES2214129B1 (en) * 2003-02-13 2005-12-01 Almirall Prodesfarma, S.A. 3-FENILFURAN-2-ONAS.
US20040220155A1 (en) * 2003-03-28 2004-11-04 Pharmacia Corporation Method of providing a steroid-sparing benefit with a cyclooxygenase-2 inhibitor and compositions therewith
GB0308186D0 (en) * 2003-04-09 2003-05-14 Smithkline Beecham Corp Novel compounds
GB0308201D0 (en) * 2003-04-09 2003-05-14 Smithkline Beecham Corp Novel compounds
GB0308185D0 (en) * 2003-04-09 2003-05-14 Smithkline Beecham Corp Novel compounds
PL1745791T3 (en) 2003-05-07 2013-11-29 Osteologix As Treating cartilage/bone conditions with water-soluble strontium salts
WO2005009342A2 (en) * 2003-07-16 2005-02-03 Pharmacia Corporation Method for the treatment or prevention of dermatological disorders with a cyclooxygenase-2 inhibitor alone and in combination with a dermatological treatment agent and compositions therewith
GB0318814D0 (en) * 2003-08-11 2003-09-10 Smithkline Beecham Corp Novel compounds
GB0319037D0 (en) * 2003-08-13 2003-09-17 Glaxo Group Ltd 7-Azaindole Derivatives
US20050119262A1 (en) * 2003-08-21 2005-06-02 Pharmacia Corporation Method for preventing or treating an optic neuropathy with a cox-2 inhibitor and an intraocular pressure reducing agent
WO2005023189A2 (en) * 2003-09-03 2005-03-17 Pharmacia Corporation Method of cox-2 selective inhibitor and nitric oxide-donating agent
GB0402143D0 (en) * 2004-01-30 2004-03-03 Smithkline Beecham Corp Novel compounds
US20080051416A1 (en) * 2004-10-05 2008-02-28 Smithkline Beecham Corporation Novel Compounds
ATE424386T1 (en) 2004-12-23 2009-03-15 Glaxo Group Ltd PYRIDINE COMPOUNDS FOR THE TREATMENT OF PROSTAGLANDIN-MEDIATED DISEASES
EP2425845A1 (en) * 2004-12-23 2012-03-07 Voyager Pharmaceutical Corporation Acetylcholinesterase Inhibitors and leuprolide acetate for the treatment of Alzheimer's disease
US20060269579A1 (en) * 2005-05-25 2006-11-30 Musculoskeletal Research Llc Compositions for treating osteoarthritis
US7767710B2 (en) * 2005-05-25 2010-08-03 Calosyn Pharma, Inc. Method for treating osteoarthritis
GB0512429D0 (en) * 2005-06-17 2005-07-27 Smithkline Beecham Corp Novel compound
GB0704407D0 (en) 2007-03-07 2007-04-18 Glaxo Group Ltd Compounds
US7943658B2 (en) 2007-07-23 2011-05-17 Bristol-Myers Squibb Company Indole indane amide compounds useful as CB2 agonists and method
WO2009042854A1 (en) * 2007-09-26 2009-04-02 Musculoskeletal Research Llc Ion-channel regulator compositions and methods of using same
UA103319C2 (en) * 2008-05-06 2013-10-10 Глаксосмитклайн Ллк Thiazole- and oxazole-benzene sulfonamide compounds
GB0813144D0 (en) 2008-07-17 2008-08-27 Glaxo Group Ltd Novel compounds
GB0813142D0 (en) 2008-07-17 2008-08-27 Glaxo Group Ltd Novel compounds
WO2011012622A1 (en) 2009-07-30 2011-02-03 Glaxo Group Limited Benzoxazinone derivatives for the treatment of glytl mediated disorders
WO2011023753A1 (en) 2009-08-27 2011-03-03 Glaxo Group Limited Benzoxazine derivatives as glycine transport inhibitors
GB201000685D0 (en) 2010-01-15 2010-03-03 Glaxo Group Ltd Novel compounds
GB201007789D0 (en) 2010-05-10 2010-06-23 Glaxo Group Ltd Novel Compound
GB201007791D0 (en) 2010-05-10 2010-06-23 Glaxo Group Ltd Novel compounds
WO2012004604A1 (en) 2010-07-09 2012-01-12 Convergence Pharmaceuticals Limited Tetrazole compounds as calcium channel blockers
US8933132B2 (en) 2011-01-19 2015-01-13 Convergence Pharmaceuticals Limited Tricyclic substituted benzenesulfonamide piperazine derivatives as CAV2.2 calcium channel blockers
GB201122113D0 (en) 2011-12-22 2012-02-01 Convergence Pharmaceuticals Novel compounds
GB201417500D0 (en) 2014-10-03 2014-11-19 Convergence Pharmaceuticals Novel use
GB201417499D0 (en) 2014-10-03 2014-11-19 Convergence Pharmaceuticals Novel use
GB201417497D0 (en) 2014-10-03 2014-11-19 Convergence Pharmaceuticals Novel use
IL305573A (en) 2021-03-15 2023-10-01 Saul Yedgar HYALURONIC ACID-CONJUGATED DIPALMITOYL PHOSPHATIDYL ETHANOLAMINE IN COMBINATION WITH NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDs) FOR TREATING OR ALLEVIATING INFLAMMATORY DISEASES

Family Cites Families (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5002941A (en) 1985-12-12 1991-03-26 Smithkline Beecham Corporation Pyrrolo(1,2-a)imidazole and imidazo(1,2-a)pyridine derivatives and their use as 5-lipoxygenase pathway inhibitors
US4925849A (en) 1987-06-15 1990-05-15 Fujisawa Pharmaceutical Company, Ltd. Pharmaceutically useful pyrazolopyridines
US5155114A (en) 1989-01-23 1992-10-13 Fujisawa Pharmaceutical Company, Ltd. Method of treatment using pyrazolopyridine compound
GB8901423D0 (en) 1989-01-23 1989-03-15 Fujisawa Pharmaceutical Co Pyrazolopyridine compound and processes for preparation thereof
WO1991000092A1 (en) 1989-06-13 1991-01-10 Smithkline Beecham Corporation Inhibition of interleukin-1 and tumor necrosis factor production by monocytes and/or macrophages
AU622330B2 (en) 1989-06-23 1992-04-02 Takeda Chemical Industries Ltd. Condensed heterocyclic compounds having a nitrogen atom in the bridgehead for use as fungicides
IL95031A (en) * 1989-07-18 2007-03-08 Amgen Inc Method for the production of a human recombinant tumor necrosis factor inhibitor
JPH05508153A (en) 1990-06-12 1993-11-18 スミスクライン・ビーチャム・コーポレイション Inhibition of diseases mediated by the 5-lipoxygenase and cyclooxygenase pathways
GB9015764D0 (en) 1990-07-18 1990-09-05 Fujisawa Pharmaceutical Co Pyrazolopyridine compound and processes for preparation thereof
FR2699077B1 (en) * 1992-12-16 1995-01-13 Rhone Poulenc Rorer Sa Application of anticonvulsants in the treatment of neurological lesions linked to trauma.
US5300478A (en) 1993-01-28 1994-04-05 Zeneca Limited Substituted fused pyrazolo compounds
US5474995A (en) * 1993-06-24 1995-12-12 Merck Frosst Canada, Inc. Phenyl heterocycles as cox-2 inhibitors
HUT74986A (en) 1994-01-10 1997-03-28 Merck Frosst Canada Inc Phenyl heterocycles as cox-2 inhibitors, pharmaceutical preparations containing them, and use of them
US5521213A (en) 1994-08-29 1996-05-28 Merck Frosst Canada, Inc. Diaryl bicyclic heterocycles as inhibitors of cyclooxygenase-2
US5552422A (en) * 1995-01-11 1996-09-03 Merck Frosst Canada, Inc. Aryl substituted 5,5 fused aromatic nitrogen compounds as anti-inflammatory agents
CZ313397A3 (en) * 1995-04-04 1998-03-18 Glaxo Group Limited IMIDAZO/1,2a/PYRIDINE DERIVATIVES, PROCESS OF THEIR PREPARATION AND PHARMACEUTICAL COMPOSITION CONTAINING THEREOF
US5700816A (en) 1995-06-12 1997-12-23 Isakson; Peter C. Treatment of inflammation and inflammation-related disorders with a combination of a cyclooxygenase-2 inhibitor and a leukotriene A4 hydrolase inhibitor
ATE301457T1 (en) 1995-06-12 2005-08-15 Searle & Co AGENT CONTAINING A CYCLOOXYGENASE-2 INHIBITOR AND A 5-LIPOXYGENASE INHIBITOR
WO1996041645A1 (en) * 1995-06-12 1996-12-27 G.D. Searle & Co. Combination of a cyclooxygenase-2 inhibitor and a leukotriene b4 receptor antagonist for the treatment of inflammations
GB9513508D0 (en) * 1995-07-03 1995-09-06 Fujisawa Pharmaceutical Co Quinazoline derivatives
KR100382619B1 (en) 1997-09-05 2003-05-09 글락소 그룹 리미티드 2,3-Diaryl-Pyrazolo[1,5-B]Pyridazines Derivatives, Their Preparation and Their Use As Cyclooxygenase 2(COX-2) Inhibitors
GB9919778D0 (en) 1999-08-21 1999-10-27 Zeneca Ltd Chemical compounds

Also Published As

Publication number Publication date
DE69833464T2 (en) 2006-08-24
PT1032575E (en) 2003-11-28
IL134688A (en) 2005-05-17
WO1999012930A1 (en) 1999-03-18
EP1369421B1 (en) 2004-11-03
YU11900A (en) 2002-11-15
US6861429B2 (en) 2005-03-01
BG104279A (en) 2000-12-29
AU9439598A (en) 1999-03-29
US20030008872A1 (en) 2003-01-09
BG64420B1 (en) 2005-01-31
EP1510519B1 (en) 2006-02-15
ES2231757T3 (en) 2005-05-16
ATE281458T1 (en) 2004-11-15
BR9812046A (en) 2000-09-26
CN1155600C (en) 2004-06-30
US6831097B2 (en) 2004-12-14
SK2942000A3 (en) 2001-03-12
NZ502985A (en) 2002-04-26
ES2256817T3 (en) 2006-07-16
JP2001515901A (en) 2001-09-25
IL134688A0 (en) 2001-04-30
NO315559B1 (en) 2003-09-22
DE69833464D1 (en) 2006-04-20
JP3167700B2 (en) 2001-05-21
HRP20000122A2 (en) 2001-02-28
DE69816651D1 (en) 2003-08-28
NO20001102L (en) 2000-05-03
US6451794B1 (en) 2002-09-17
AU744997B2 (en) 2002-03-07
EE200000113A (en) 2000-12-15
ES2203985T3 (en) 2004-04-16
EP1032575A1 (en) 2000-09-06
EA002775B1 (en) 2002-08-29
TR200000595T2 (en) 2000-12-21
US20050113377A1 (en) 2005-05-26
AP1354A (en) 2004-12-29
HUP0003644A3 (en) 2002-11-28
DE69827419T2 (en) 2005-10-27
US20030040517A1 (en) 2003-02-27
SK283922B6 (en) 2004-05-04
DK1032575T3 (en) 2003-10-20
KR20010023669A (en) 2001-03-26
DE69827419D1 (en) 2004-12-09
EP1369421A1 (en) 2003-12-10
AP2000001753A0 (en) 2000-03-31
ATE245649T1 (en) 2003-08-15
NO20001102D0 (en) 2000-03-03
HRP20000122B1 (en) 2003-06-30
EE04617B1 (en) 2006-04-17
EA200000188A1 (en) 2000-10-30
ATE317845T1 (en) 2006-03-15
KR100382619B1 (en) 2003-05-09
CN1278263A (en) 2000-12-27
TW570922B (en) 2004-01-11
PL194557B1 (en) 2007-06-29
CA2303152A1 (en) 1999-03-18
DE69816651T2 (en) 2004-04-01
HUP0003644A2 (en) 2001-09-28
IS5389A (en) 2000-02-25
PL339059A1 (en) 2000-12-04
EP1510519A1 (en) 2005-03-02

Similar Documents

Publication Publication Date Title
EP1032575B1 (en) 2,3-diaryl-pyrazolo(1,5-b)pyridazines derivatives, their preparation and their use as cyclooxygenase 2 (cox-2) inhibitors
RU2539568C2 (en) Pyrazolpyrimidine compounds jak inhibitors and methods
JPH11501049A (en) Imidazo [1,2-a] pyridine derivative
CN101678014A (en) heterocyclic kinase modulators
US6869956B2 (en) Methods of treating inflammatory and immune diseases using inhibitors of IκB kinase (IKK)
CA2436770A1 (en) Methods of treating inflammatory and immune diseases using inhibitors of ikb kinase (ikk)
CN111320633B (en) Pyrrole/imidazo six-membered heteroaromatic ring compound and preparation method and medical application thereof
KR101914161B1 (en) Novel compound acting as a cannabinoid receptor-1 inhibitor
MXPA00002203A (en) 2,3-diaryl-pyrazolo[1,5-b]pyridazines derivatives, their preparation and their use as cyclooxygenase 2 (cox-2) inhibitors
JP3167700B1 (en) 2,3-Diaryl-pyrazolo [1,5-B] pyridazine derivatives, their preparation and their use as cyclooxygenase 2 (COX-2) inhibitors
CZ2000800A3 (en) 2,3-diarylpyrazolo /1,5 - b/ pyridazine derivatives
WO2020187291A1 (en) Pyrazolopyrimidine compound, pharmaceutical composition, and application therefor
JP2023538097A (en) Pyrimidinone compounds and uses thereof
ZA200103344B (en) Pyrazolopyridine derivatives as selective COX-2 inhibitors.

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20000303

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL PAYMENT 20000303;LT PAYMENT 20000303;LV PAYMENT 20000303;MK PAYMENT 20000303;RO PAYMENT 20000303;SI PAYMENT 20000303

17Q First examination report despatched

Effective date: 20010611

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: ISLER & PEDRAZZINI AG

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69816651

Country of ref document: DE

Date of ref document: 20030828

Kind code of ref document: P

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: GR

Ref legal event code: EP

Ref document number: 20030404041

Country of ref document: GR

LTIE Lt: invalidation of european patent or patent extension

Effective date: 20030723

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2203985

Country of ref document: ES

Kind code of ref document: T3

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20040426

REG Reference to a national code

Ref country code: SI

Ref legal event code: IF

REG Reference to a national code

Ref country code: HK

Ref legal event code: WD

Ref document number: 1028770

Country of ref document: HK

REG Reference to a national code

Ref country code: CH

Ref legal event code: PCAR

Free format text: ISLER & PEDRAZZINI AG;POSTFACH 1772;8027 ZUERICH (CH)

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CY

Payment date: 20070903

Year of fee payment: 10

Ref country code: PT

Payment date: 20080627

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: LU

Payment date: 20080731

Year of fee payment: 11

Ref country code: DK

Payment date: 20080811

Year of fee payment: 11

Ref country code: CH

Payment date: 20080708

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20080813

Year of fee payment: 11

Ref country code: MC

Payment date: 20080811

Year of fee payment: 11

Ref country code: IE

Payment date: 20080718

Year of fee payment: 11

Ref country code: FI

Payment date: 20080903

Year of fee payment: 11

Ref country code: AT

Payment date: 20080811

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20080905

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GR

Payment date: 20080704

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080903

REG Reference to a national code

Ref country code: PT

Ref legal event code: MM4A

Free format text: LAPSE DUE TO NON-PAYMENT OF FEES

Effective date: 20100303

REG Reference to a national code

Ref country code: NL

Ref legal event code: V1

Effective date: 20100401

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100303

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090930

Ref country code: FI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090903

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

EUG Se: european patent has lapsed
REG Reference to a national code

Ref country code: DK

Ref legal event code: EBP

REG Reference to a national code

Ref country code: SI

Ref legal event code: KO00

Effective date: 20100422

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090903

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100401

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090903

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090930

Ref country code: GR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100406

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090930

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20100930

Year of fee payment: 13

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090903

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090904

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20110826

Year of fee payment: 14

Ref country code: ES

Payment date: 20110915

Year of fee payment: 14

Ref country code: FR

Payment date: 20110901

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20110920

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20110927

Year of fee payment: 14

BERE Be: lapsed

Owner name: *GLAXO GROUP LTD

Effective date: 20120930

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20120903

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20130531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20130403

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120903

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120930

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 69816651

Country of ref document: DE

Effective date: 20130403

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120903

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121001

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20131018

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120904